20-F 1 mt-20211231.htm 20-F mt-20211231
00012434292021FYFALSEP1YtwononoP3YP3YP3YP2YP5YP3YP2YP3YP3YP3YP3YP3YP3YP3YP1Y1.57140.3300012434292021-01-012021-12-310001243429dei:BusinessContactMember2021-01-012021-12-310001243429exch:XNYS2021-01-012021-12-310001243429mt:A55MandatorilyConvertibleSubordinatedNotesDue2023Memberexch:XNYS2021-01-012021-12-3100012434292021-12-31xbrli:sharesiso4217:USD00012434292020-01-012020-12-3100012434292019-01-012019-12-31iso4217:USDxbrli:shares00012434292020-12-310001243429ifrs-full:IssuedCapitalMember2018-12-310001243429ifrs-full:TreasurySharesMember2018-12-310001243429ifrs-full:ReserveOfEquityComponentOfConvertibleInstrumentsMember2018-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2018-12-310001243429ifrs-full:RetainedEarningsMember2018-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2018-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2018-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2018-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2018-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2018-12-310001243429ifrs-full:NoncontrollingInterestsMember2018-12-3100012434292018-12-310001243429ifrs-full:RetainedEarningsMember2019-01-012019-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2019-01-012019-12-310001243429ifrs-full:NoncontrollingInterestsMember2019-01-012019-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2019-01-012019-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2019-01-012019-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2019-01-012019-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2019-01-012019-12-310001243429ifrs-full:IssuedCapitalMember2019-01-012019-12-310001243429ifrs-full:TreasurySharesMember2019-01-012019-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2019-01-012019-12-310001243429ifrs-full:IssuedCapitalMember2019-12-310001243429ifrs-full:TreasurySharesMember2019-12-310001243429ifrs-full:ReserveOfEquityComponentOfConvertibleInstrumentsMember2019-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2019-12-310001243429ifrs-full:RetainedEarningsMember2019-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2019-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2019-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2019-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2019-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2019-12-310001243429ifrs-full:NoncontrollingInterestsMember2019-12-3100012434292019-12-310001243429ifrs-full:RetainedEarningsMember2020-01-012020-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2020-01-012020-12-310001243429ifrs-full:NoncontrollingInterestsMember2020-01-012020-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2020-01-012020-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2020-01-012020-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2020-01-012020-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2020-01-012020-12-310001243429ifrs-full:IssuedCapitalMember2020-01-012020-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2020-01-012020-12-310001243429ifrs-full:TreasurySharesMember2020-01-012020-12-310001243429ifrs-full:ReserveOfEquityComponentOfConvertibleInstrumentsMember2020-01-012020-12-310001243429ifrs-full:IssuedCapitalMember2020-12-310001243429ifrs-full:TreasurySharesMember2020-12-310001243429ifrs-full:ReserveOfEquityComponentOfConvertibleInstrumentsMember2020-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2020-12-310001243429ifrs-full:RetainedEarningsMember2020-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2020-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2020-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2020-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2020-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2020-12-310001243429ifrs-full:NoncontrollingInterestsMember2020-12-310001243429ifrs-full:RetainedEarningsMember2021-01-012021-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2021-01-012021-12-310001243429ifrs-full:NoncontrollingInterestsMember2021-01-012021-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2021-01-012021-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2021-01-012021-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2021-01-012021-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2021-01-012021-12-310001243429ifrs-full:IssuedCapitalMember2021-01-012021-12-310001243429ifrs-full:TreasurySharesMember2021-01-012021-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2021-01-012021-12-310001243429ifrs-full:ReserveOfEquityComponentOfConvertibleInstrumentsMember2021-01-012021-12-310001243429ifrs-full:IssuedCapitalMember2021-12-310001243429ifrs-full:TreasurySharesMember2021-12-310001243429ifrs-full:ReserveOfEquityComponentOfConvertibleInstrumentsMember2021-12-310001243429ifrs-full:AdditionalPaidinCapitalMember2021-12-310001243429ifrs-full:RetainedEarningsMember2021-12-310001243429ifrs-full:ReserveOfExchangeDifferencesOnTranslationMember2021-12-310001243429ifrs-full:ReserveOfCashFlowHedgesMember2021-12-310001243429ifrs-full:ReserveOfGainsAndLossesOnFinancialAssetsMeasuredAtFairValueThroughOtherComprehensiveIncomeMember2021-12-310001243429ifrs-full:ReserveOfRemeasurementsOfDefinedBenefitPlansMember2021-12-310001243429ifrs-full:EquityAttributableToOwnersOfParentMember2021-12-310001243429ifrs-full:NoncontrollingInterestsMember2021-12-310001243429mt:MandatorilyConvertibleUnsecuredUnsubordinatedBondsMember2011-09-270001243429mt:NAFTAMembermt:ArcelorMittalDofascoG.P.Member2021-01-012021-12-31xbrli:pure0001243429mt:ArcelorMittalMexicoS.A.deC.V.Membermt:NAFTAMember2021-01-012021-12-310001243429mt:ArcelorMittalLongProductsCanadaG.P.Membermt:NAFTAMember2021-01-012021-12-310001243429mt:ArcelorMittalBrasilS.A.Membermt:BrazilSegmentMember2021-01-012021-12-310001243429mt:BrazilSegmentMembermt:AcindarIndustriaArgentinadeAcerosS.A.Member2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:ArcelorMittalFranceS.A.S.Member2021-01-012021-12-310001243429mt:ArcelorMittalBelgiumN.V.Membermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ArcelorMittalEspaaS.A.Membermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ArcelorMittalFlatCarbonEuropeS.A.Membermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ArcelorMittalPolandS.A.Membermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ArcelorMittalEisenhttenstadtGmbHMembermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:ArcelorMittalBremenGmbHMember2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:ArcelorMittalMediterraneS.A.S.Member2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:ArcelorMittalBelvalDifferdangeS.A.Member2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:ArcelorMittalHamburgGmbHMember2021-01-012021-12-310001243429mt:ArcelorMittalDuisburgGmbHMembermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ArcelorMittalInternationalLuxembourgS.A.Membermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ACISMembermt:ArcelorMittalSouthAfricaLtd.Member2021-01-012021-12-310001243429mt:ACISMembermt:JSCArcelorMittalTemirtauMember2021-01-012021-12-310001243429mt:ACISMembermt:PJSCArcelorMittalKryvyiRihMember2021-01-012021-12-310001243429mt:MiningMembermt:ArcelorMittalMiningCanadaGPAndArcelorMittalInfrastructureCanadaGPAMMCMember2021-01-012021-12-310001243429mt:MiningMembermt:ArcelorMittalLiberiaLtdMember2021-01-012021-12-310001243429mt:AcindarIndustriaArgentinadeAcerosS.A.Member2021-12-310001243429mt:AcindarIndustriaArgentinadeAcerosS.A.Member2020-12-310001243429mt:AcindarIndustriaArgentinadeAcerosS.A.Member2021-01-012021-12-310001243429mt:AcindarIndustriaArgentinadeAcerosS.A.Member2020-01-012020-12-310001243429mt:IndustriasUniconCAMember2021-12-310001243429mt:IndustriasUniconCAMember2020-12-310001243429mt:IndustriasUniconCAMember2019-12-310001243429mt:CondesaTubosSLCondesaMember2021-11-182021-11-180001243429mt:CondesaTubosSLCondesaMember2021-11-19iso4217:EUR0001243429mt:CondesaTubosSLCondesaMember2021-11-192021-11-190001243429mt:CondesaTubosSLCondesaMember2021-11-192021-12-310001243429mt:CondesaTubosSLCondesaMember2021-01-012021-12-310001243429mt:MunkerMetallprofileGmBHMember2019-06-040001243429mt:MunkerMetallprofileGmBHMember2019-06-042019-06-040001243429mt:MunkerMetallprofileGmBHMemberifrs-full:GoodwillMember2019-12-310001243429mt:MunkerMetallprofileGmBHMember2019-12-310001243429mt:MunkerMetallprofileGmBHMembermt:CurrentAssetsMember2019-12-310001243429mt:MunkerMetallprofileGmBHMember2019-06-042019-12-310001243429mt:MunkerMetallprofileGmBHMember2019-01-012019-12-3100012434292020-03-042020-03-040001243429mt:ArcelorMittalItaliaS.p.AMember2020-12-1400012434292020-12-14mt:capital_increase0001243429ifrs-full:DisposalGroupsClassifiedAsHeldForSaleMembermt:AMInvestcoItalyS.p.A.Member2021-04-142021-04-140001243429ifrs-full:DisposalGroupsClassifiedAsHeldForSaleMembermt:AMInvestcoItalyS.p.A.Member2022-01-012022-05-310001243429ifrs-full:DisposalGroupsClassifiedAsHeldForSaleMemberifrs-full:TopOfRangeMembermt:AMInvestcoItalyS.p.A.Member2022-01-012022-05-310001243429ifrs-full:GoodwillMembermt:EuropeSegmentMember2020-01-012020-12-310001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:AcciaierieDItaliaHoldingMember2021-04-140001243429mt:AcciaierieDItaliaHoldingMember2021-04-142021-04-140001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:AcciaierieDItaliaHoldingMember2021-04-142021-04-140001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:AMUSADivestmentBusinessMember2020-12-092020-12-090001243429ifrs-full:OrdinarySharesMembermt:ClevelandCliffsIncMembermt:AMUSADivestmentBusinessMember2020-12-090001243429mt:ClevelandCliffsIncMembermt:AMUSADivestmentBusinessMemberifrs-full:PreferenceSharesMember2020-12-090001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:AMUSADivestmentBusinessMember2021-04-012021-06-3000012434292020-12-092020-12-090001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:AMUSADivestmentBusinessMember2020-12-090001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:ArcelorMittalItaliaRemediesMember2018-05-07mt:divestment_package0001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:ArcelorMittalItaliaRemediesMember2019-06-300001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:ArcelorMittalItaliaRemediesMember2019-06-302019-06-300001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:ArcelorMittalItaliaRemediesMember2019-06-282019-06-280001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:ArcelorMittalItaliaRemediesMember2019-01-012019-12-310001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:GlobalCharteringLimitedMember2019-12-312019-12-310001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:GlobalCharteringLimitedMember2020-01-012020-12-310001243429mt:GlobalCharteringLimitedMember2019-12-312019-12-310001243429mt:GlobalCharteringLimitedMemberifrs-full:MiscellaneousOtherProvisionsMember2020-01-012020-12-310001243429mt:DisposalGroupDisposedofbySaleNotDiscontinuedOperationsMembermt:GlobalCharteringLimitedMember2019-12-310001243429ifrs-full:CostOfSalesMember2020-12-312020-12-310001243429ifrs-full:DisposalGroupsClassifiedAsHeldForSaleMembermt:ArcelorMittalItaliaRemediesAndPlateOperationsInEuropeMember2020-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2021-01-012021-12-310001243429mt:AcciaierieDItaliaHoldingMember2021-01-012021-12-310001243429mt:CalvertMember2021-01-012021-12-310001243429mt:ValinArcelorMittalAutomotiveSteelMember2021-01-012021-12-310001243429mt:TamehMember2021-01-012021-12-310001243429mt:BorcelikCelikSanayiiTicaretAnonimSirketiMember2021-01-012021-12-310001243429mt:ArcelorMittalTubularProductsAlJubailMember2021-01-012021-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2021-12-310001243429mt:AcciaierieDItaliaHoldingMember2021-12-310001243429mt:CalvertMember2021-12-310001243429mt:ValinArcelorMittalAutomotiveSteelMember2021-12-310001243429mt:TamehMember2021-12-310001243429mt:BorcelikCelikSanayiiTicaretAnonimSirketiMember2021-12-310001243429mt:ArcelorMittalTubularProductsAlJubailMember2021-12-310001243429ifrs-full:JointVenturesMember2021-12-310001243429ifrs-full:JointVenturesMember2021-01-012021-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2020-01-012020-12-310001243429mt:CalvertMember2020-01-012020-12-310001243429mt:ValinArcelorMittalAutomotiveSteelMember2020-01-012020-12-310001243429mt:TamehMember2020-01-012020-12-310001243429mt:BorcelikCelikSanayiiTicaretAnonimSirketiMember2020-01-012020-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2020-12-310001243429mt:CalvertMember2020-12-310001243429mt:ValinArcelorMittalAutomotiveSteelMember2020-12-310001243429mt:TamehMember2020-12-310001243429mt:BorcelikCelikSanayiiTicaretAnonimSirketiMember2020-12-310001243429ifrs-full:JointVenturesMember2020-12-310001243429ifrs-full:JointVenturesMember2020-01-012020-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-01-012019-12-310001243429mt:CalvertMember2019-01-012019-12-310001243429mt:ValinArcelorMittalAutomotiveSteelMember2019-01-012019-12-310001243429mt:TamehMember2019-01-012019-12-310001243429mt:BorcelikCelikSanayiiTicaretAnonimSirketiMember2019-01-012019-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-12-310001243429mt:CalvertMember2019-12-310001243429mt:ValinArcelorMittalAutomotiveSteelMember2019-12-310001243429mt:TamehMember2019-12-310001243429mt:BorcelikCelikSanayiiTicaretAnonimSirketiMember2019-12-310001243429ifrs-full:JointVenturesMember2019-12-310001243429ifrs-full:JointVenturesMember2019-01-012019-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-12-082019-12-080001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:NipponSteelCorporationMember2019-12-082019-12-080001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-12-162019-12-160001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-12-160001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:NipponSteelCorporationMember2019-12-160001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-01-012019-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:NipponSteelCorporationMember2019-01-012019-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:NipponSteelCorporationMember2019-12-162019-12-160001243429mt:ArcelorMittalNipponSteelIndiaLimitedMemberifrs-full:RetainedEarningsMembermt:NipponSteelCorporationMember2019-01-012019-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:ArcelorMittalAndNipponSteelCorporationMember2019-12-160001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:SevenBillionTermFacilityDue2020Member2019-12-162019-12-160001243429mt:SevenBillionTermFacilityDue2020Member2018-11-200001243429mt:ArcelorMittalNipponSteelIndiaLimitedMemberifrs-full:JointVenturesWhereEntityIsVenturerMembermt:NipponSteelCorporationMember2019-12-162019-12-16mt:plantmt:service_centermt:plant_system0001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2018-10-262018-10-260001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2018-10-26mt:stage0001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:UttamGalvaMember2019-12-190001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:NipponSteelCorporationMembermt:UttamGalvaMember2019-12-190001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:ArcelorMittalAndNipponSteelCorporationMembermt:UttamGalvaMember2019-12-190001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:SevenBillionTermFacilityDue2020Membermt:UttamGalvaMember2019-12-192019-12-190001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:UttamGalvaMemberifrs-full:JointVenturesWhereEntityIsVenturerMember2019-12-192019-12-190001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2019-12-312019-12-310001243429mt:ArcelorMittalNipponSteelIndiaLimitedMember2020-02-130001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:SevenBillionTermFacilityDue2020Member2020-02-132020-02-130001243429mt:ArcelorMittalNipponSteelIndiaLimitedMemberifrs-full:JointVenturesWhereEntityIsVenturerMembermt:NipponSteelCorporationMember2020-02-132020-02-130001243429mt:FivePointOneFourSixBillionTermLoanDue2030Member2020-03-160001243429mt:FivePointOneFourSixBillionTermLoanDue2030Member2020-03-162020-03-160001243429mt:SevenBillionBridgeTermFacilitiesMember2020-03-270001243429mt:OdishaSlurryPipelineInfrastructureLimitedMember2020-07-072020-07-070001243429mt:ArcelorMittalNipponSteelIndiaLimitedMembermt:ParadeepOdishaMember2021-09-012021-09-30utr:t0001243429country:INmt:ArcelorMittalNipponSteelIndiaLimitedMember2021-09-012021-09-300001243429mt:CalvertMember2020-12-092020-12-09mt:facility0001243429mt:ArcelorMittalTubularProductsAlJubailMemberifrs-full:JointVenturesWhereEntityIsVenturerMember2020-12-310001243429mt:ArcelorMittalTubularProductsAlJubailMemberifrs-full:JointVenturesWhereEntityIsVenturerMember2019-12-310001243429mt:ArcelorMittalTubularProductsAlJubailMemberifrs-full:JointVenturesWhereEntityIsVenturerMember2021-01-012021-12-310001243429mt:ArcelorMittalTubularProductsAlJubailMember2020-01-012020-12-310001243429mt:ChinaOrientalGroupCompanyLimitedMember2021-01-012021-12-310001243429mt:DHSGroupMember2021-01-012021-12-310001243429mt:GonvarriSteelIndustriesMember2021-01-012021-12-310001243429mt:BaffinlandMember2021-01-012021-12-310001243429mt:ChinaOrientalGroupCompanyLimitedMember2021-12-310001243429mt:DHSGroupMember2021-12-310001243429mt:GonvarriSteelIndustriesMember2021-12-310001243429mt:BaffinlandMember2021-12-310001243429ifrs-full:AssociatesMember2021-12-310001243429ifrs-full:AssociatesMember2021-01-012021-12-310001243429mt:DHSGroupMember2020-01-012020-12-310001243429mt:BaffinlandMember2020-09-012020-09-300001243429mt:ChinaOrientalGroupCompanyLimitedMember2020-01-012020-12-310001243429mt:GonvarriSteelIndustriesMember2020-01-012020-12-310001243429mt:BaffinlandMember2020-01-012020-12-310001243429mt:ChinaOrientalGroupCompanyLimitedMember2020-12-310001243429mt:DHSGroupMember2020-12-310001243429mt:GonvarriSteelIndustriesMember2020-12-310001243429mt:BaffinlandMember2020-12-310001243429ifrs-full:AssociatesMember2020-12-310001243429ifrs-full:AssociatesMember2020-01-012020-12-310001243429mt:ChinaOrientalGroupCompanyLimitedMember2019-01-012019-12-310001243429mt:DHSGroupMember2019-01-012019-12-310001243429mt:GonvarriSteelIndustriesMember2019-01-012019-12-310001243429mt:BaffinlandMember2019-01-012019-12-310001243429mt:ChinaOrientalGroupCompanyLimitedMember2019-12-310001243429mt:DHSGroupMember2019-12-310001243429mt:GonvarriSteelIndustriesMember2019-12-310001243429mt:BaffinlandMember2019-12-310001243429ifrs-full:AssociatesMember2019-12-310001243429ifrs-full:AssociatesMember2019-01-012019-12-310001243429mt:DHSGroupMember2020-12-312020-12-310001243429mt:BaffinlandMember2018-01-012018-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMember2021-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2021-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMemberifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2021-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMember2020-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2020-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMemberifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2020-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMember2021-01-012021-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2021-01-012021-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMemberifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2021-01-012021-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMember2020-01-012020-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2020-01-012020-12-310001243429ifrs-full:AggregatedIndividuallyImmaterialAssociatesMemberifrs-full:AggregatedIndividuallyImmaterialJointVenturesMember2020-01-012020-12-310001243429mt:PeaColoradaMember2021-01-012021-12-310001243429mt:PeaColoradaMember2020-01-012020-12-310001243429mt:HibbingTaconiteMinesMember2020-01-012020-12-310001243429mt:HibbingTaconiteMinesMember2021-01-012021-12-310001243429mt:INTekMember2021-01-012021-12-310001243429mt:INTekMember2020-01-012020-12-310001243429mt:DoubleGCoatingMember2020-01-012020-12-310001243429mt:DoubleGCoatingMember2021-01-012021-12-310001243429mt:OtherInvestments1Membermt:EregliDemirveCelikFabrikalariT.A.S.Member2021-12-310001243429mt:OtherInvestments1Membermt:EregliDemirveCelikFabrikalariT.A.S.Member2020-12-310001243429mt:OtherInvestments1Membermt:ArcelorMitalXCarbMember2021-12-310001243429mt:OtherInvestments1Membermt:ArcelorMitalXCarbMember2020-12-310001243429mt:OtherInvestments1Membermt:StalproduktSAMember2021-12-310001243429mt:OtherInvestments1Membermt:StalproduktSAMember2020-12-310001243429mt:OtherInvestments1Membermt:ClevelandCliffsIncMember2021-12-310001243429mt:OtherInvestments1Membermt:ClevelandCliffsIncMember2020-12-310001243429mt:OtherInvestments1Membermt:OtherInvestmentIssuersMember2021-12-310001243429mt:OtherInvestments1Membermt:OtherInvestmentIssuersMember2020-12-310001243429mt:OtherInvestments1Member2021-12-310001243429mt:OtherInvestments1Member2020-12-310001243429mt:OtherInvestments1Membermt:EregliDemirveCelikFabrikalariT.A.S.Member2021-01-012021-12-310001243429mt:OtherInvestments1Membermt:EregliDemirveCelikFabrikalariT.A.S.Member2020-01-012020-12-310001243429ifrs-full:OrdinarySharesMembermt:ClevelandCliffsIncMember2020-12-090001243429mt:ClevelandCliffsIncMemberifrs-full:PreferenceSharesMember2020-12-090001243429ifrs-full:OrdinarySharesMembermt:ClevelandCliffsIncMember2020-01-012020-12-310001243429mt:ClevelandCliffsIncMemberifrs-full:PreferenceSharesMember2020-01-012020-12-310001243429mt:OtherInvestments1Membermt:ClevelandCliffsIncMember2021-02-092021-06-180001243429mt:OtherInvestments1Membermt:ClevelandCliffsIncMember2021-06-182021-06-180001243429mt:OtherInvestments1Membermt:ClevelandCliffsIncMemberifrs-full:PreferenceSharesMember2021-07-282021-07-280001243429mt:OtherInvestments1Membermt:ClevelandCliffsIncMember2021-07-282021-07-280001243429mt:OtherInvestments1Membermt:ArcelorMitalXCarbMembersrt:MaximumMember2021-12-310001243429mt:OtherInvestments1Membermt:ArcelorMitalXCarbMember2021-01-012021-12-310001243429mt:OtherInvestments1Membermt:StalproduktSAMember2021-01-012021-12-310001243429mt:OtherInvestments1Membermt:StalproduktSAMember2020-01-012020-12-310001243429mt:OtherInvestments1Membermt:PowercellSwedenMember2019-01-012019-12-310001243429mt:OtherInvestments1Membermt:PowercellSwedenMember2020-01-012020-12-310001243429mt:OtherInvestments1Membermt:GerdauMember2019-07-162019-07-16mt:vesselmt:segment0001243429mt:NAFTAMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:EuropeSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ACISMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:MiningMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429ifrs-full:AllOtherSegmentsMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:NAFTAMemberifrs-full:EliminationOfIntersegmentAmountsMember2021-01-012021-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:BrazilSegmentMember2021-01-012021-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:EuropeSegmentMember2021-01-012021-12-310001243429mt:ACISMemberifrs-full:EliminationOfIntersegmentAmountsMember2021-01-012021-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:MiningMember2021-01-012021-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMemberifrs-full:AllOtherSegmentsMember2021-01-012021-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMember2021-01-012021-12-310001243429mt:NAFTAMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:EuropeSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ACISMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:MiningMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429ifrs-full:AllOtherSegmentsMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:NAFTAMemberifrs-full:EliminationOfIntersegmentAmountsMember2020-01-012020-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:BrazilSegmentMember2020-01-012020-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:EuropeSegmentMember2020-01-012020-12-310001243429mt:ACISMemberifrs-full:EliminationOfIntersegmentAmountsMember2020-01-012020-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:MiningMember2020-01-012020-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMemberifrs-full:AllOtherSegmentsMember2020-01-012020-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMember2020-01-012020-12-310001243429mt:NAFTAMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:EuropeSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ACISMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:MiningMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429ifrs-full:AllOtherSegmentsMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:NAFTAMemberifrs-full:EliminationOfIntersegmentAmountsMember2019-01-012019-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:BrazilSegmentMember2019-01-012019-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:EuropeSegmentMember2019-01-012019-12-310001243429mt:ACISMemberifrs-full:EliminationOfIntersegmentAmountsMember2019-01-012019-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMembermt:MiningMember2019-01-012019-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMemberifrs-full:AllOtherSegmentsMember2019-01-012019-12-310001243429ifrs-full:EliminationOfIntersegmentAmountsMember2019-01-012019-12-310001243429country:US2021-01-012021-12-310001243429country:US2020-01-012020-12-310001243429country:US2019-01-012019-12-310001243429country:BR2021-01-012021-12-310001243429country:BR2020-01-012020-12-310001243429country:BR2019-01-012019-12-310001243429country:CA2021-01-012021-12-310001243429country:CA2020-01-012020-12-310001243429country:CA2019-01-012019-12-310001243429country:MX2021-01-012021-12-310001243429country:MX2020-01-012020-12-310001243429country:MX2019-01-012019-12-310001243429country:AR2021-01-012021-12-310001243429country:AR2020-01-012020-12-310001243429country:AR2019-01-012019-12-310001243429mt:OtherAmericasMember2021-01-012021-12-310001243429mt:OtherAmericasMember2020-01-012020-12-310001243429mt:OtherAmericasMember2019-01-012019-12-310001243429srt:AmericasMember2021-01-012021-12-310001243429srt:AmericasMember2020-01-012020-12-310001243429srt:AmericasMember2019-01-012019-12-310001243429country:DE2021-01-012021-12-310001243429country:DE2020-01-012020-12-310001243429country:DE2019-01-012019-12-310001243429country:PL2021-01-012021-12-310001243429country:PL2020-01-012020-12-310001243429country:PL2019-01-012019-12-310001243429country:FR2021-01-012021-12-310001243429country:FR2020-01-012020-12-310001243429country:FR2019-01-012019-12-310001243429country:ES2021-01-012021-12-310001243429country:ES2020-01-012020-12-310001243429country:ES2019-01-012019-12-310001243429country:IT2021-01-012021-12-310001243429country:IT2020-01-012020-12-310001243429country:IT2019-01-012019-12-310001243429country:CZ2021-01-012021-12-310001243429country:CZ2020-01-012020-12-310001243429country:CZ2019-01-012019-12-310001243429country:TR2021-01-012021-12-310001243429country:TR2020-01-012020-12-310001243429country:TR2019-01-012019-12-310001243429country:GB2021-01-012021-12-310001243429country:GB2020-01-012020-12-310001243429country:GB2019-01-012019-12-310001243429country:BE2021-01-012021-12-310001243429country:BE2020-01-012020-12-310001243429country:BE2019-01-012019-12-310001243429country:NL2021-01-012021-12-310001243429country:NL2020-01-012020-12-310001243429country:NL2019-01-012019-12-310001243429country:RU2021-01-012021-12-310001243429country:RU2020-01-012020-12-310001243429country:RU2019-01-012019-12-310001243429country:RO2021-01-012021-12-310001243429country:RO2020-01-012020-12-310001243429country:RO2019-01-012019-12-310001243429country:UA2021-01-012021-12-310001243429country:UA2020-01-012020-12-310001243429country:UA2019-01-012019-12-310001243429mt:OtherEuropeMember2021-01-012021-12-310001243429mt:OtherEuropeMember2020-01-012020-12-310001243429mt:OtherEuropeMember2019-01-012019-12-310001243429srt:EuropeMember2021-01-012021-12-310001243429srt:EuropeMember2020-01-012020-12-310001243429srt:EuropeMember2019-01-012019-12-310001243429country:ZA2021-01-012021-12-310001243429country:ZA2020-01-012020-12-310001243429country:ZA2019-01-012019-12-310001243429country:MA2021-01-012021-12-310001243429country:MA2020-01-012020-12-310001243429country:MA2019-01-012019-12-310001243429country:EG2021-01-012021-12-310001243429country:EG2020-01-012020-12-310001243429country:EG2019-01-012019-12-310001243429mt:RestofAfricaMember2021-01-012021-12-310001243429mt:RestofAfricaMember2020-01-012020-12-310001243429mt:RestofAfricaMember2019-01-012019-12-310001243429country:CN2021-01-012021-12-310001243429country:CN2020-01-012020-12-310001243429country:CN2019-01-012019-12-310001243429country:KZ2021-01-012021-12-310001243429country:KZ2020-01-012020-12-310001243429country:KZ2019-01-012019-12-310001243429country:KR2021-01-012021-12-310001243429country:KR2020-01-012020-12-310001243429country:KR2019-01-012019-12-310001243429country:IN2021-01-012021-12-310001243429country:IN2020-01-012020-12-310001243429country:IN2019-01-012019-12-310001243429mt:RestofAsiaMember2021-01-012021-12-310001243429mt:RestofAsiaMember2020-01-012020-12-310001243429mt:RestofAsiaMember2019-01-012019-12-310001243429mt:AsiaandAfricaMember2021-01-012021-12-310001243429mt:AsiaandAfricaMember2020-01-012020-12-310001243429mt:AsiaandAfricaMember2019-01-012019-12-310001243429country:LU2021-01-012021-12-310001243429country:LU2020-01-012020-12-310001243429country:LU2019-01-012019-12-310001243429country:CA2021-12-310001243429country:CA2020-12-310001243429country:BR2021-12-310001243429country:BR2020-12-310001243429country:US2021-12-310001243429country:US2020-12-310001243429country:MX2021-12-310001243429country:MX2020-12-310001243429country:AR2021-12-310001243429country:AR2020-12-310001243429country:VE2021-12-310001243429country:VE2020-12-310001243429mt:OtherAmericasMember2021-12-310001243429mt:OtherAmericasMember2020-12-310001243429srt:AmericasMember2021-12-310001243429srt:AmericasMember2020-12-310001243429country:FR2021-12-310001243429country:FR2020-12-310001243429country:DE2021-12-310001243429country:DE2020-12-310001243429country:BE2021-12-310001243429country:BE2020-12-310001243429country:PL2021-12-310001243429country:PL2020-12-310001243429country:UA2021-12-310001243429country:UA2020-12-310001243429country:ES2021-12-310001243429country:ES2020-12-310001243429country:LU2021-12-310001243429country:LU2020-12-310001243429country:BA2021-12-310001243429country:BA2020-12-310001243429country:RO2021-12-310001243429country:RO2020-12-310001243429country:CZ2021-12-310001243429country:CZ2020-12-310001243429mt:OtherEuropeMember2021-12-310001243429mt:OtherEuropeMember2020-12-310001243429srt:EuropeMember2021-12-310001243429srt:EuropeMember2020-12-310001243429country:KZ2021-12-310001243429country:KZ2020-12-310001243429country:ZA2021-12-310001243429country:ZA2020-12-310001243429country:LR2021-12-310001243429country:LR2020-12-310001243429country:MA2021-12-310001243429country:MA2020-12-310001243429mt:OtherAsiaandAfricaMember2021-12-310001243429mt:OtherAsiaandAfricaMember2020-12-310001243429mt:AsiaandAfricaMember2021-12-310001243429mt:AsiaandAfricaMember2020-12-310001243429mt:FlatproductsMember2021-01-012021-12-310001243429mt:FlatproductsMember2020-01-012020-12-310001243429mt:FlatproductsMember2019-01-012019-12-310001243429mt:LongproductsMember2021-01-012021-12-310001243429mt:LongproductsMember2020-01-012020-12-310001243429mt:LongproductsMember2019-01-012019-12-310001243429mt:TubularproductsMember2021-01-012021-12-310001243429mt:TubularproductsMember2020-01-012020-12-310001243429mt:TubularproductsMember2019-01-012019-12-310001243429mt:MiningproductsMember2021-01-012021-12-310001243429mt:MiningproductsMember2020-01-012020-12-310001243429mt:MiningproductsMember2019-01-012019-12-310001243429mt:OtherproductsMember2021-01-012021-12-310001243429mt:OtherproductsMember2020-01-012020-12-310001243429mt:OtherproductsMember2019-01-012019-12-310001243429mt:NAFTAMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:SteelSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ACISMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:MiningMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:SteelSalesMemberifrs-full:UnallocatedAmountsMember2021-01-012021-12-310001243429mt:SteelSalesMember2021-01-012021-12-310001243429mt:NAFTAMembermt:NonSteelSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:NonSteelSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:NonSteelSalesMembermt:EuropeSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ACISMembermt:NonSteelSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:NonSteelSalesMembermt:MiningMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:NonSteelSalesMemberifrs-full:UnallocatedAmountsMember2021-01-012021-12-310001243429mt:NonSteelSalesMember2021-01-012021-12-310001243429mt:NAFTAMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ByProductSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ACISMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:MiningMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ByProductSalesMemberifrs-full:UnallocatedAmountsMember2021-01-012021-12-310001243429mt:ByProductSalesMember2021-01-012021-12-310001243429mt:NAFTAMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:OtherSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:EuropeSegmentMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:ACISMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:MiningMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2021-01-012021-12-310001243429mt:OtherSalesMemberifrs-full:UnallocatedAmountsMember2021-01-012021-12-310001243429mt:OtherSalesMember2021-01-012021-12-310001243429ifrs-full:UnallocatedAmountsMember2021-01-012021-12-310001243429mt:NAFTAMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:SteelSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:EuropeSegmentMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ACISMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:MiningMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:SteelSalesMemberifrs-full:UnallocatedAmountsMember2020-01-012020-12-310001243429mt:SteelSalesMember2020-01-012020-12-310001243429mt:NAFTAMembermt:NonSteelSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:NonSteelSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:NonSteelSalesMembermt:EuropeSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ACISMembermt:NonSteelSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:NonSteelSalesMembermt:MiningMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:NonSteelSalesMemberifrs-full:UnallocatedAmountsMember2020-01-012020-12-310001243429mt:NonSteelSalesMember2020-01-012020-12-310001243429mt:NAFTAMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ByProductSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:EuropeSegmentMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ACISMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:MiningMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ByProductSalesMemberifrs-full:UnallocatedAmountsMember2020-01-012020-12-310001243429mt:ByProductSalesMember2020-01-012020-12-310001243429mt:NAFTAMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:OtherSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:EuropeSegmentMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:ACISMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:MiningMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2020-01-012020-12-310001243429mt:OtherSalesMemberifrs-full:UnallocatedAmountsMember2020-01-012020-12-310001243429mt:OtherSalesMember2020-01-012020-12-310001243429ifrs-full:UnallocatedAmountsMember2020-01-012020-12-310001243429mt:NAFTAMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:SteelSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:EuropeSegmentMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ACISMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:MiningMembermt:SteelSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:SteelSalesMemberifrs-full:UnallocatedAmountsMember2019-01-012019-12-310001243429mt:SteelSalesMember2019-01-012019-12-310001243429mt:NAFTAMembermt:NonSteelSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:NonSteelSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:NonSteelSalesMembermt:EuropeSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ACISMembermt:NonSteelSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:NonSteelSalesMembermt:MiningMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:NonSteelSalesMemberifrs-full:UnallocatedAmountsMember2019-01-012019-12-310001243429mt:NonSteelSalesMember2019-01-012019-12-310001243429mt:NAFTAMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ByProductSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:EuropeSegmentMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ACISMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:MiningMembermt:ByProductSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ByProductSalesMemberifrs-full:UnallocatedAmountsMember2019-01-012019-12-310001243429mt:ByProductSalesMember2019-01-012019-12-310001243429mt:NAFTAMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:OtherSalesMembermt:BrazilSegmentMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:EuropeSegmentMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:ACISMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:MiningMembermt:OtherSalesMemberifrs-full:OperatingSegmentsMember2019-01-012019-12-310001243429mt:OtherSalesMemberifrs-full:UnallocatedAmountsMember2019-01-012019-12-310001243429mt:OtherSalesMember2019-01-012019-12-310001243429ifrs-full:UnallocatedAmountsMember2019-01-012019-12-310001243429ifrs-full:NotLaterThanOneYearMember2021-12-310001243429mt:AMUSADivestmentBusinessMember2021-01-012021-12-310001243429mt:AMUSADivestmentBusinessMember2020-01-012020-12-310001243429mt:AMUSADivestmentBusinessMember2019-01-012019-12-310001243429ifrs-full:FinancialAssetsIndividuallyAssessedForCreditLossesMemberifrs-full:LaterThanSixMonthsMember2021-01-012021-12-310001243429ifrs-full:FinancialAssetsIndividuallyAssessedForCreditLossesMembermt:LessThanSixMonthsMember2021-01-012021-12-310001243429mt:LaterThanOneMonthMemberifrs-full:FinancialAssetsIndividuallyAssessedForCreditLossesMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:TradeReceivablesMember2020-12-310001243429mt:NAFTAMemberifrs-full:TradeReceivablesMember2021-12-310001243429mt:NAFTAMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:TradeReceivablesMembermt:BrazilSegmentMember2021-12-310001243429ifrs-full:TradeReceivablesMembermt:BrazilSegmentMember2020-12-310001243429ifrs-full:TradeReceivablesMembermt:EuropeSegmentMember2021-12-310001243429ifrs-full:TradeReceivablesMembermt:EuropeSegmentMember2020-12-310001243429mt:ACISMemberifrs-full:TradeReceivablesMember2021-12-310001243429mt:ACISMemberifrs-full:TradeReceivablesMember2020-12-310001243429mt:MiningMemberifrs-full:TradeReceivablesMember2021-12-310001243429mt:MiningMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CurrentMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:CurrentMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrentMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CurrentMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:CurrentMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrentMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:NotLaterThanOneMonthMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:NotLaterThanOneMonthMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:NotLaterThanOneMonthMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:NotLaterThanOneMonthMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:NotLaterThanOneMonthMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:NotLaterThanOneMonthMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanOneMonthAndNotLaterThanTwoMonthsMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanOneMonthAndNotLaterThanTwoMonthsMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:LaterThanOneMonthAndNotLaterThanTwoMonthsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanOneMonthAndNotLaterThanTwoMonthsMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanOneMonthAndNotLaterThanTwoMonthsMember2020-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:LaterThanOneMonthAndNotLaterThanTwoMonthsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember2020-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:LaterThanTwoMonthsAndNotLaterThanThreeMonthsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:TradeReceivablesMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:TradeReceivablesMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanSixMonthsMember2021-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanSixMonthsMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:LaterThanSixMonthsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanSixMonthsMember2020-12-310001243429ifrs-full:AccumulatedImpairmentMemberifrs-full:TradeReceivablesMemberifrs-full:LaterThanSixMonthsMember2020-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:LaterThanSixMonthsMember2020-12-310001243429ifrs-full:TradeReceivablesMember2019-12-310001243429ifrs-full:TradeReceivablesMember2018-12-310001243429ifrs-full:TradeReceivablesMember2021-01-012021-12-310001243429ifrs-full:TradeReceivablesMember2020-01-012020-12-310001243429ifrs-full:TradeReceivablesMember2019-01-012019-12-310001243429ifrs-full:BottomOfRangeMember2021-01-012021-12-310001243429ifrs-full:TopOfRangeMember2021-01-012021-12-310001243429mt:ArcelorMittalSulFluminenseMember2021-12-310001243429ifrs-full:GoodwillMember2021-12-310001243429ifrs-full:GoodwillMember2020-12-310001243429mt:ConcessionsPatentsAndLicensesMember2021-12-310001243429mt:ConcessionsPatentsAndLicensesMember2020-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMember2021-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMember2020-12-310001243429ifrs-full:OtherIntangibleAssetsMember2021-12-310001243429ifrs-full:OtherIntangibleAssetsMember2020-12-310001243429mt:OtherIntangibleAssetsEmissionRightsMember2021-12-310001243429ifrs-full:GoodwillMembermt:NAFTAMember2020-12-310001243429ifrs-full:GoodwillMembermt:NAFTAMember2021-01-012021-12-310001243429ifrs-full:GoodwillMembermt:NAFTAMember2021-12-310001243429ifrs-full:GoodwillMembermt:BrazilSegmentMember2020-12-310001243429ifrs-full:GoodwillMembermt:BrazilSegmentMember2021-01-012021-12-310001243429ifrs-full:GoodwillMembermt:BrazilSegmentMember2021-12-310001243429ifrs-full:GoodwillMembermt:EuropeSegmentMember2020-12-310001243429ifrs-full:GoodwillMembermt:EuropeSegmentMember2021-01-012021-12-310001243429ifrs-full:GoodwillMembermt:EuropeSegmentMember2021-12-310001243429ifrs-full:GoodwillMembermt:ACISMember2020-12-310001243429ifrs-full:GoodwillMembermt:ACISMember2021-01-012021-12-310001243429ifrs-full:GoodwillMembermt:ACISMember2021-12-310001243429ifrs-full:GoodwillMember2021-01-012021-12-310001243429ifrs-full:GoodwillMembermt:NAFTAMember2019-12-310001243429ifrs-full:GoodwillMembermt:NAFTAMember2020-01-012020-12-310001243429ifrs-full:GoodwillMembermt:BrazilSegmentMember2019-12-310001243429ifrs-full:GoodwillMembermt:BrazilSegmentMember2020-01-012020-12-310001243429ifrs-full:GoodwillMembermt:EuropeSegmentMember2019-12-310001243429ifrs-full:GoodwillMembermt:ACISMember2019-12-310001243429ifrs-full:GoodwillMembermt:ACISMember2020-01-012020-12-310001243429ifrs-full:GoodwillMember2019-12-310001243429ifrs-full:GoodwillMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMembermt:ConcessionsPatentsAndLicensesMember2019-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CustomerrelatedIntangibleAssetsMember2019-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:OtherIntangibleAssetsMember2019-12-310001243429ifrs-full:GrossCarryingAmountMember2019-12-310001243429ifrs-full:GrossCarryingAmountMembermt:ConcessionsPatentsAndLicensesMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CustomerrelatedIntangibleAssetsMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:OtherIntangibleAssetsMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMembermt:ConcessionsPatentsAndLicensesMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CustomerrelatedIntangibleAssetsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:OtherIntangibleAssetsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMember2020-12-310001243429ifrs-full:GrossCarryingAmountMembermt:ConcessionsPatentsAndLicensesMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CustomerrelatedIntangibleAssetsMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:OtherIntangibleAssetsMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMembermt:ConcessionsPatentsAndLicensesMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:CustomerrelatedIntangibleAssetsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:OtherIntangibleAssetsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMember2021-12-310001243429mt:ConcessionsPatentsAndLicensesMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:OtherIntangibleAssetsMember2019-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429mt:ConcessionsPatentsAndLicensesMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:OtherIntangibleAssetsMember2020-01-012020-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429mt:ConcessionsPatentsAndLicensesMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:OtherIntangibleAssetsMember2020-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429mt:ConcessionsPatentsAndLicensesMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:OtherIntangibleAssetsMember2021-01-012021-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429mt:ConcessionsPatentsAndLicensesMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429ifrs-full:CustomerrelatedIntangibleAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:OtherIntangibleAssetsMember2021-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429ifrs-full:BottomOfRangeMemberifrs-full:BuildingsMember2021-01-012021-12-310001243429ifrs-full:TopOfRangeMemberifrs-full:BuildingsMember2021-01-012021-12-310001243429ifrs-full:BottomOfRangeMemberifrs-full:OtherPropertyPlantAndEquipmentMember2021-01-012021-12-310001243429ifrs-full:TopOfRangeMemberifrs-full:OtherPropertyPlantAndEquipmentMember2021-01-012021-12-310001243429ifrs-full:BottomOfRangeMembermt:AuxiliaryFacilitiesMember2021-01-012021-12-310001243429ifrs-full:TopOfRangeMembermt:AuxiliaryFacilitiesMember2021-01-012021-12-310001243429ifrs-full:BottomOfRangeMembermt:OtherFacilitiesMember2021-01-012021-12-310001243429ifrs-full:TopOfRangeMembermt:OtherFacilitiesMember2021-01-012021-12-3100012434292021-10-012021-12-310001243429srt:ScenarioForecastMember2022-01-012022-12-310001243429srt:ScenarioForecastMember2023-01-012023-12-310001243429srt:ScenarioForecastMember2024-01-012024-12-310001243429srt:ScenarioForecastMember2025-01-012025-12-310001243429srt:ScenarioForecastMember2026-01-012026-12-310001243429srt:ScenarioForecastMember2027-01-012027-12-310001243429srt:ScenarioForecastMember2028-01-012028-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LandAndBuildingsMember2019-12-310001243429ifrs-full:GrossCarryingAmountMembermt:MachineryEquipmentAndOtherMember2019-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:ConstructionInProgressMember2019-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:RightofuseAssetsMember2019-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:MiningAssetsMember2019-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LandAndBuildingsMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMembermt:MachineryEquipmentAndOtherMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:ConstructionInProgressMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:RightofuseAssetsMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:MiningAssetsMember2020-01-012020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LandAndBuildingsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMembermt:MachineryEquipmentAndOtherMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:ConstructionInProgressMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:RightofuseAssetsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:MiningAssetsMember2020-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LandAndBuildingsMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMembermt:MachineryEquipmentAndOtherMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:ConstructionInProgressMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:RightofuseAssetsMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:MiningAssetsMember2021-01-012021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:LandAndBuildingsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMembermt:MachineryEquipmentAndOtherMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:ConstructionInProgressMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:RightofuseAssetsMember2021-12-310001243429ifrs-full:GrossCarryingAmountMemberifrs-full:MiningAssetsMember2021-12-310001243429ifrs-full:LandAndBuildingsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429mt:MachineryEquipmentAndOtherMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429ifrs-full:ConstructionInProgressMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429ifrs-full:RightofuseAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2019-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:MiningAssetsMember2019-12-310001243429ifrs-full:LandAndBuildingsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429mt:MachineryEquipmentAndOtherMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429ifrs-full:ConstructionInProgressMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429ifrs-full:RightofuseAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-01-012020-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:MiningAssetsMember2020-01-012020-12-310001243429ifrs-full:LandAndBuildingsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429mt:MachineryEquipmentAndOtherMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429ifrs-full:ConstructionInProgressMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429ifrs-full:RightofuseAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2020-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:MiningAssetsMember2020-12-310001243429ifrs-full:LandAndBuildingsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429mt:MachineryEquipmentAndOtherMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429ifrs-full:ConstructionInProgressMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429ifrs-full:RightofuseAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-01-012021-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:MiningAssetsMember2021-01-012021-12-310001243429ifrs-full:LandAndBuildingsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429mt:MachineryEquipmentAndOtherMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429ifrs-full:ConstructionInProgressMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429ifrs-full:RightofuseAssetsMemberifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMember2021-12-310001243429ifrs-full:AccumulatedDepreciationAmortisationAndImpairmentMemberifrs-full:MiningAssetsMember2021-12-310001243429ifrs-full:LandAndBuildingsMember2020-12-310001243429mt:MachineryEquipmentAndOtherMember2020-12-310001243429ifrs-full:ConstructionInProgressMember2020-12-310001243429ifrs-full:RightofuseAssetsMember2020-12-310001243429ifrs-full:MiningAssetsMember2020-12-310001243429ifrs-full:LandAndBuildingsMember2021-12-310001243429mt:MachineryEquipmentAndOtherMember2021-12-310001243429ifrs-full:ConstructionInProgressMember2021-12-310001243429ifrs-full:RightofuseAssetsMember2021-12-310001243429ifrs-full:MiningAssetsMember2021-12-310001243429mt:BrazilSegmentMember2021-12-310001243429mt:BrazilSegmentMember2020-12-310001243429mt:NAFTAMember2021-12-310001243429mt:NAFTAMember2020-12-310001243429mt:EuropeSegmentMember2021-12-310001243429mt:EuropeSegmentMember2020-12-310001243429mt:ACISMember2021-12-310001243429mt:ACISMember2020-12-310001243429mt:TangibleAssetsMember2021-01-012021-12-310001243429mt:TangibleAssetsMember2020-01-012020-12-310001243429mt:TangibleAssetsMember2019-01-012019-12-310001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMemberifrs-full:BottomOfRangeMember2021-10-01mt:uSDPerTonne0001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMemberifrs-full:TopOfRangeMember2021-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMember2021-12-310001243429srt:EuropeMember2021-12-310001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:NAFTAMember2021-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:BrazilSegmentMember2021-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:EuropeSegmentMember2021-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:ACISMember2021-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:NAFTAMember2020-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:BrazilSegmentMember2020-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:EuropeSegmentMember2020-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMembermt:ACISMember2020-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMember2021-10-012021-10-010001243429ifrs-full:IndividualAssetsOrCashgeneratingUnitsWithSignificantAmountOfGoodwillOrIntangibleAssetsWithIndefiniteUsefulLivesMember2020-10-012020-10-01mt:cash_generating_unit0001243429mt:EuropeFlatProductsMembersrt:EuropeMembermt:Europe1Member2021-07-012021-12-310001243429mt:EuropeFlatProductsMembersrt:EuropeMembermt:Europe1Member2021-10-010001243429mt:EuropeFlatProductsMembersrt:EuropeMembermt:Europe1Member2020-10-010001243429mt:EuropeFlatProductsMembersrt:EuropeMembermt:Europe1Member2021-12-310001243429mt:FlorangeMember2020-01-012020-12-310001243429mt:KrakowMember2020-01-012020-12-310001243429mt:Europe1Member2020-01-012020-12-310001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMember2020-07-012020-09-300001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMember2019-01-012019-12-310001243429mt:ACISMembermt:ArcelorMittalSouthAfricaLtd.Member2019-01-012019-12-310001243429mt:ArcelorMittalItaliaRemediesMembermt:Europe1Member2019-01-012019-12-310001243429mt:ArcelorMittalItaliaRemediesMember2019-01-012019-12-310001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMembercountry:US2019-01-012019-06-300001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMembercountry:US2019-06-300001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMembercountry:US2018-12-310001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMembercountry:US2019-07-012019-12-310001243429mt:NAFTAMembermt:ArcelorMittalUSALLCMembercountry:US2019-12-310001243429mt:LongSteelProductsMembermt:ACISMembercountry:ZA2019-01-012019-12-310001243429mt:LongSteelProductsMembermt:ACISMembercountry:ZA2019-12-310001243429mt:LongSteelProductsMembermt:ACISMembercountry:ZA2018-12-310001243429mt:ArcelorMittalSouthAfricaLtd.Member2019-01-012019-12-310001243429mt:SaldanhaMember2019-01-012019-12-310001243429mt:NonFinancialAssetsMember2021-12-310001243429ifrs-full:FinancialAssetsAtAmortisedCostCategoryMembermt:FinancialAssets1Member2021-12-310001243429mt:FinancialAssets1Memberifrs-full:FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember2021-12-310001243429ifrs-full:FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMembermt:FinancialAssets1Member2021-12-310001243429mt:FinancialAssets1Member2021-12-310001243429mt:DerivativesCategoryMembermt:FinancialAssets1Member2021-12-310001243429mt:NonFinancialLiabilitiesMember2021-12-310001243429ifrs-full:FinancialLiabilitiesAtAmortisedCostCategoryMembermt:FinancialLiabilities1Member2021-12-310001243429mt:FinancialLiabilities1Memberifrs-full:FinancialLiabilitiesAtFairValueThroughProfitOrLossCategoryMember2021-12-310001243429mt:DerivativesCategoryMembermt:FinancialLiabilities1Member2021-12-310001243429mt:NonFinancialAssetsMember2020-12-310001243429ifrs-full:FinancialAssetsAtAmortisedCostCategoryMembermt:FinancialAssets1Member2020-12-310001243429mt:FinancialAssets1Memberifrs-full:FinancialAssetsAtFairValueThroughProfitOrLossCategoryMember2020-12-310001243429ifrs-full:FinancialAssetsAtFairValueThroughOtherComprehensiveIncomeCategoryMembermt:FinancialAssets1Member2020-12-310001243429mt:DerivativesCategoryMembermt:FinancialAssets1Member2020-12-310001243429mt:NonFinancialLiabilitiesMember2020-12-310001243429ifrs-full:FinancialLiabilitiesAtAmortisedCostCategoryMembermt:FinancialLiabilities1Member2020-12-310001243429mt:FinancialLiabilities1Memberifrs-full:FinancialLiabilitiesAtFairValueThroughProfitOrLossCategoryMember2020-12-310001243429mt:DerivativesCategoryMembermt:FinancialLiabilities1Member2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Memberifrs-full:Level1OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Member2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Memberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Member2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMemberifrs-full:Level1OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429mt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMemberifrs-full:RecurringFairValueMeasurementMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMembermt:DerivativeFinancialAssetsCurrentMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsCurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsCurrentMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsCurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMembermt:DerivativeFinancialAssetsNoncurrentMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsNoncurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMembermt:DerivativeFinancialAssetsNoncurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsNoncurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMember2021-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMember2021-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMember2021-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:RecurringFairValueMeasurementMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMembermt:DerivativefinancialliabilitiesnoncurrentMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:DerivativefinancialliabilitiesnoncurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMembermt:DerivativefinancialliabilitiesnoncurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativefinancialliabilitiesnoncurrentMember2021-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Memberifrs-full:Level1OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Member2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Memberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:InvestmentsInEquityInstrumentsDesignatedAtFairValueThroughOtherComprehensiveIncome1Member2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMemberifrs-full:Level1OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:TradeAndOtherCurrentReceivablesSubjectToTSRProgramsMemberifrs-full:RecurringFairValueMeasurementMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMembermt:DerivativeFinancialAssetsCurrentMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsCurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsCurrentMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsCurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMembermt:DerivativeFinancialAssetsNoncurrentMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsNoncurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMembermt:DerivativeFinancialAssetsNoncurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativeFinancialAssetsNoncurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMember2020-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMember2020-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMember2020-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:DerivativefinancialliabilitiescurrentMemberifrs-full:RecurringFairValueMeasurementMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level1OfFairValueHierarchyMembermt:DerivativefinancialliabilitiesnoncurrentMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:RecurringFairValueMeasurementMembermt:DerivativefinancialliabilitiesnoncurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMemberifrs-full:Level3OfFairValueHierarchyMembermt:DerivativefinancialliabilitiesnoncurrentMember2020-12-310001243429ifrs-full:RecurringFairValueMeasurementMembermt:DerivativefinancialliabilitiesnoncurrentMember2020-12-310001243429ifrs-full:WeightedAverageMember2021-01-012021-12-310001243429ifrs-full:WeightedAverageMember2020-01-012020-12-310001243429mt:ThreeHundredMillionEURTermLoanDue2021Member2020-04-080001243429mt:ShortTermBilateralCreditFacilitiesMember2021-12-310001243429mt:CommercialPaper1Member2021-12-310001243429mt:CommercialPaper1Member2020-12-310001243429mt:FivePointFiveBillionRevolvingCreditFacilityDue20232024Member2021-12-310001243429mt:FivePointFiveBillionRevolvingCreditFacilityDue20232024Member2020-12-310001243429mt:FiveHundredMillionEURUnsecuredNotesDue2021Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:FiveHundredMillionEURUnsecuredNotesDue2021Member2021-12-310001243429mt:FiveHundredMillionEURUnsecuredNotesDue2021Member2020-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2022Member2021-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2022Memberifrs-full:FixedInterestRateMember2021-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2022Member2020-12-310001243429mt:FiveHundredMillionEURUnsecuredNotesDue2025Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:FiveHundredMillionEURUnsecuredNotesDue2025Member2021-12-310001243429mt:FiveHundredMillionEURUnsecuredNotesDue2025Member2020-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2023Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionEURUnsecuredNotesDue2023Member2021-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2023Member2020-12-310001243429mt:OneBillionEURUnsecuredNotesDue2024Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:OneBillionEURUnsecuredNotesDue2024Member2021-12-310001243429mt:OneBillionEURUnsecuredNotesDue2024Member2020-12-310001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2021-12-310001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2020-12-310001243429mt:FiveHundredMillionUnsecuredNotesDue2025Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:FiveHundredMillionUnsecuredNotesDue2025Member2021-12-310001243429mt:FiveHundredMillionUnsecuredNotesDue2025Member2020-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2025Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionEURUnsecuredNotesDue2025Member2021-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2025Member2020-12-310001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2021-12-310001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2020-12-310001243429mt:FiveHundredMillionUnsecuredNotesDue2029Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:FiveHundredMillionUnsecuredNotesDue2029Member2021-12-310001243429mt:FiveHundredMillionUnsecuredNotesDue2029Member2020-12-310001243429mt:OnePointFiveBillionUnsecuredBondsDue2039Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:OnePointFiveBillionUnsecuredBondsDue2039Member2021-12-310001243429mt:OnePointFiveBillionUnsecuredBondsDue2039Member2020-12-310001243429mt:OneBillionUnsecuredNotesDue2041Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:OneBillionUnsecuredNotesDue2041Member2021-12-310001243429mt:OneBillionUnsecuredNotesDue2041Member2020-12-310001243429ifrs-full:FixedInterestRateMemberifrs-full:BottomOfRangeMembermt:OtherLoansDue2021To2022Member2021-12-310001243429ifrs-full:FixedInterestRateMemberifrs-full:TopOfRangeMembermt:OtherLoansDue2021To2022Member2021-12-310001243429mt:OtherLoansDue2021To2022Member2021-12-310001243429mt:OtherLoansDue2021To2022Member2020-12-310001243429ifrs-full:FixedInterestRateMembermt:EIBLoanDue2025Member2021-12-310001243429mt:EIBLoanDue2025Member2021-12-310001243429mt:EIBLoanDue2025Member2020-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:BottomOfRangeMembermt:OtherLoansDue20212035Member2021-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:TopOfRangeMembermt:OtherLoansDue20212035Member2021-12-310001243429mt:OtherLoansDue20212035Member2021-12-310001243429mt:OtherLoansDue20212035Member2020-12-310001243429mt:CorporateBorrowingsMember2021-12-310001243429mt:CorporateBorrowingsMember2020-12-310001243429srt:AmericasMemberifrs-full:BottomOfRangeMembermt:OtherLoansFixedFloatingDue20202030Membermt:FixedFloatingInterestRatesMember2021-12-310001243429srt:AmericasMemberifrs-full:TopOfRangeMembermt:OtherLoansFixedFloatingDue20202030Membermt:FixedFloatingInterestRatesMember2021-12-310001243429srt:AmericasMembermt:OtherLoansFixedFloatingDue20202030Member2021-12-310001243429srt:AmericasMembermt:OtherLoansFixedFloatingDue20202030Member2020-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:BottomOfRangeMembermt:EuropeAsiaAndAfricaMembermt:EBRDFacilityFloatingDueIn2024Member2021-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:TopOfRangeMembermt:EuropeAsiaAndAfricaMembermt:EBRDFacilityFloatingDueIn2024Member2021-12-310001243429mt:EuropeAsiaAndAfricaMembermt:EBRDFacilityFloatingDueIn2024Member2021-12-310001243429mt:EuropeAsiaAndAfricaMembermt:EBRDFacilityFloatingDueIn2024Member2020-12-310001243429ifrs-full:BottomOfRangeMembermt:EuropeAsiaAndAfricaMembermt:OtherLoansFixedFloatingDue20202029Membermt:FixedFloatingInterestRatesMember2021-12-310001243429ifrs-full:TopOfRangeMembermt:EuropeAsiaAndAfricaMembermt:OtherLoansFixedFloatingDue20202029Membermt:FixedFloatingInterestRatesMember2021-12-310001243429mt:OtherLoansFixedFloatingDue20202029Membermt:EuropeAsiaAndAfricaMember2021-12-310001243429mt:OtherLoansFixedFloatingDue20202029Membermt:EuropeAsiaAndAfricaMember2020-12-310001243429mt:EuropeAsiaAndAfricaMember2021-12-310001243429mt:EuropeAsiaAndAfricaMember2020-12-310001243429mt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429mt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429mt:LongTermDebtExcludingLeaseObligationMember2021-12-310001243429mt:LongTermDebtExcludingLeaseObligationMember2020-12-310001243429ifrs-full:LeaseLiabilitiesMember2021-12-310001243429ifrs-full:LeaseLiabilitiesMember2020-12-310001243429mt:FivePointFourBillionRevolvingCreditFacilityDue2024Member2020-11-262020-11-260001243429mt:FivePointFiveBillionRevolvingCreditFacilityDue2023Member2019-11-270001243429mt:FivePointFourBillionRevolvingCreditFacilityDue2024Member2019-11-270001243429mt:FivePointFiveBillionRevolvingCreditFacilityDue20232024Member2018-12-190001243429mt:FivePointFiveBillionRevolvingCreditFacilityDue20232024Member2018-12-192018-12-19mt:extension_option0001243429mt:FivePointFourBillionRevolvingCreditFacilityDue2024Member2020-12-310001243429mt:ZeroPointOneBillionRevolvingCreditFacilityDue2023Member2020-12-310001243429mt:TwoThousandAndTenRevolvingMulticurrencyLetterOfCreditFacilityMember2010-09-300001243429mt:TwoThousandAndTenRevolvingMulticurrencyLetterOfCreditFacilityMember2012-10-260001243429mt:TwoThousandAndTenRevolvingMulticurrencyLetterOfCreditFacilityMember2014-09-300001243429mt:RevolvingMulticurrencyLetterOfCreditFacilityDueIn2022Member2019-07-310001243429mt:TwoThousandAndTenRevolvingMulticurrencyLetterOfCreditFacilityMember2020-11-250001243429mt:SixHundredMillionEURUnsecuredNotesDue2020Member2021-04-092021-04-090001243429mt:SixHundredMillionEURUnsecuredNotesDue2020Member2021-04-090001243429mt:OneBillionEURUnsecuredNotesDue2024Member2021-06-292021-06-290001243429ifrs-full:FixedInterestRateMembermt:OneBillionEURUnsecuredNotesDue2024Member2021-06-290001243429mt:OneBillionEURUnsecuredNotesDue2024Member2021-06-290001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2021-06-292021-06-290001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2021-06-290001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2021-06-290001243429mt:FiveHundredMillionUnsecuredNotesDue2025Member2021-06-292021-06-290001243429ifrs-full:FixedInterestRateMembermt:FiveHundredMillionUnsecuredNotesDue2025Member2021-06-290001243429mt:FiveHundredMillionUnsecuredNotesDue2025Member2021-06-290001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2021-06-292021-06-290001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2021-06-290001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2021-06-290001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2022Member2015-01-140001243429mt:FiveHundredMillionEURUnsecuredNotesDue2023Member2021-12-310001243429mt:FiveHundredMillionEURUnsecuredNotesDue2023Member2017-12-040001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2023Member2019-11-190001243429mt:TwoHundredFiftyMillionEURUnsecuredNotesDue2024Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:TwoHundredFiftyMillionEURUnsecuredNotesDue2024Member2021-12-310001243429mt:TwoHundredFiftyMillionEURUnsecuredNotesDue2024Member2019-07-040001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2024Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:SevenHundredFiftyMillionEURUnsecuredNotesDue2024Member2021-12-310001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2024Member2019-01-170001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2024Member2019-07-160001243429mt:FiveHundredMillionUnsecuredNotesDue2025Member2015-06-010001243429mt:SevenHundredFiftyMillionEURUnsecuredNotesDue2025Member2019-11-190001243429mt:SevenHundredFiftyMillionUnsecuredNotesDue2026Member2019-03-110001243429mt:FiveHundredMillionUnsecuredNotesDue2029Member2019-07-160001243429mt:OneBillionUnsecuredBondsDue2039Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:OneBillionUnsecuredBondsDue2039Member2021-12-310001243429mt:OneBillionUnsecuredBondsDue2039Member2009-10-080001243429mt:FiveHundredMillionUnsecuredBondsDue2039Member2021-12-310001243429ifrs-full:FixedInterestRateMembermt:FiveHundredMillionUnsecuredBondsDue2039Member2021-12-310001243429mt:FiveHundredMillionUnsecuredBondsDue2039Member2010-08-050001243429mt:OneBillionUnsecuredNotesDue2041Member2011-03-070001243429mt:EIBLoanMember2021-06-020001243429mt:EIBLoanMembermt:ProceedsFromBorrowingsMember2022-03-012022-03-010001243429mt:EIBLoanDue2025Member2016-12-160001243429mt:OtherLoansFixedFloatingDue20212035Member2021-07-072021-07-070001243429mt:OtherLoansFixedFloatingDueJuly2023Member2021-07-072021-07-070001243429mt:OtherLoansFixedFloatingDueJuly2025Member2021-07-072021-07-070001243429mt:TwoHundredThirtyFiveMillionEURFacilityAgreementMember2018-12-210001243429mt:TwoHundredThirtyFiveMillionEURFacilityAgreementMember2018-12-182018-12-180001243429mt:TwoHundredThirtyFiveMillionEURFacilityAgreementMember2021-12-310001243429mt:OneHundredTwentyFiveMillionEURBilateralTermLoanDue2022Member2020-07-312020-07-310001243429mt:OneHundredTwentyFiveMillionEURBilateralTermLoanDue2022Member2021-12-310001243429mt:OneHundredMillionEURBilateralTermLoanDue2023Member2019-12-200001243429mt:OneHundredMillionEURBilateralTermLoanDue2023Member2019-12-202019-12-200001243429mt:OneHundredSeventyFourMillionCADFinancingAgreementDue20212022Member2020-07-02iso4217:CAD0001243429mt:OneHundredAndThirtyMillionCADFinancingAgreementDue20212023Member2021-11-290001243429mt:PJSCArcelorMittalKryvyiRihMembermt:EBRDFacilityFloatingDueIn2024Member2017-12-210001243429mt:PJSCArcelorMittalKryvyiRihMembermt:EBRDFacilityFloatingDueIn2024Member2021-12-310001243429mt:FourPointFiveBillionSouthAfricaRandRevolvingBorrowingBaseFinanceFacilityDueIn2022Membermt:ArcelorMittalSouthAfricaLtd.Member2017-05-25iso4217:ZAR0001243429mt:ThreePointFiveBillionSouthAfricaRandRevolvingBorrowingBaseFinanceFacilityDueIn2023Membermt:ArcelorMittalSouthAfricaLtd.Member2021-08-230001243429mt:FourPointFiveBillionSouthAfricaRandRevolvingBorrowingBaseFinanceFacilityDueIn2022Membermt:ArcelorMittalSouthAfricaLtd.Member2021-12-310001243429ifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429ifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-01-012021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMember2021-12-310001243429ifrs-full:LaterThanTwoYearsAndNotLaterThanThreeYearsMember2021-12-310001243429ifrs-full:LaterThanThreeYearsAndNotLaterThanFourYearsMember2021-12-310001243429ifrs-full:LaterThanFourYearsAndNotLaterThanFiveYearsMember2021-12-310001243429ifrs-full:LaterThanFiveYearsMember2021-12-310001243429ifrs-full:FixedInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:FixedInterestRateMemberifrs-full:Level1OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:FixedInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:FixedInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:FloatingInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:Level1OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:FloatingInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:FloatingInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429mt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:Level1OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2021-12-310001243429mt:LongTermBorrowingsIncludingCurrentPortionMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429mt:CurrentBorrowingsMember2021-12-310001243429mt:CurrentBorrowingsMemberifrs-full:Level1OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:CurrentBorrowingsMember2021-12-310001243429mt:CurrentBorrowingsMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:FixedInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:FixedInterestRateMemberifrs-full:Level1OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:FixedInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:FixedInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429ifrs-full:FloatingInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:Level1OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMemberifrs-full:FloatingInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:FloatingInterestRateMembermt:LongTermBorrowingsIncludingCurrentPortionMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:Level1OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:LongTermBorrowingsIncludingCurrentPortionMember2020-12-310001243429mt:LongTermBorrowingsIncludingCurrentPortionMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:CurrentBorrowingsMember2020-12-310001243429mt:CurrentBorrowingsMemberifrs-full:Level1OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:CurrentBorrowingsMember2020-12-310001243429mt:CurrentBorrowingsMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:ArcelorMittalSouthAfricaLtd.Member2021-12-310001243429mt:ArcelorMittalSouthAfricaLtd.Member2020-12-310001243429mt:ArcelorMittalUSALLCMember2020-12-310001243429ifrs-full:LongtermBorrowingsMember2019-12-310001243429ifrs-full:ShorttermBorrowingsMember2019-12-310001243429ifrs-full:LongtermBorrowingsMember2020-01-012020-12-310001243429ifrs-full:ShorttermBorrowingsMember2020-01-012020-12-310001243429ifrs-full:LongtermBorrowingsMember2020-12-310001243429ifrs-full:ShorttermBorrowingsMember2020-12-310001243429ifrs-full:LongtermBorrowingsMember2021-01-012021-12-310001243429ifrs-full:ShorttermBorrowingsMember2021-01-012021-12-310001243429ifrs-full:LongtermBorrowingsMember2021-12-310001243429ifrs-full:ShorttermBorrowingsMember2021-12-310001243429currency:EUR2021-12-310001243429currency:USD2021-12-310001243429currency:PLN2021-12-310001243429currency:CAD2021-12-310001243429currency:ZAR2021-12-310001243429mt:OtherCurrenciesMember2021-12-310001243429currency:EUR2020-12-310001243429currency:USD2020-12-310001243429currency:CAD2020-12-310001243429currency:PLN2020-12-310001243429currency:UAH2020-12-310001243429mt:OtherCurrenciesMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ForwardPurchaseContractMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ForwardSalesContractMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ExchangeOptionPurchasesMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ExchangeOptionSalesMember2021-12-310001243429mt:ForeignExchangeRateInstrumentsMemberifrs-full:Level2OfFairValueHierarchyMember2021-12-310001243429mt:TermContractsSalesMemberifrs-full:Level2OfFairValueHierarchyMember2021-12-310001243429mt:TermContractsPurchasesMemberifrs-full:Level2OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:RawMaterialsFreightEnergyEmissionRightsMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:OtherInterestRateInstrumentsMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:TotalInterestRateInstrumentsMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ForwardPurchaseContractMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ForwardSalesContractMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:CurrencySwapSalesMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ExchangeOptionPurchasesMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:ExchangeOptionSalesMember2020-12-310001243429mt:ForeignExchangeRateInstrumentsMemberifrs-full:Level2OfFairValueHierarchyMember2020-12-310001243429mt:TermContractsSalesMemberifrs-full:Level2OfFairValueHierarchyMember2020-12-310001243429mt:TermContractsPurchasesMemberifrs-full:Level2OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:OptionsSalesPurchasesMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:RawMaterialsFreightEnergyEmissionRightsMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMember2020-12-310001243429mt:MandatorilyConvertibleUnsecuredUnsubordinatedBondsMember2021-12-310001243429mt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2021-01-012021-12-310001243429ifrs-full:MatrixPricingMembermt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:WrittenPutOptionsMemberifrs-full:Level3OfFairValueHierarchyMember2019-12-310001243429mt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2019-12-310001243429mt:SpecialPaymentInPelletPurchasesAndSaleAgreementMemberifrs-full:Level3OfFairValueHierarchyMember2019-12-310001243429ifrs-full:Level3OfFairValueHierarchyMember2019-12-310001243429ifrs-full:WrittenPutOptionsMemberifrs-full:Level3OfFairValueHierarchyMember2020-01-012020-12-310001243429mt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2020-01-012020-12-310001243429mt:SpecialPaymentInPelletPurchasesAndSaleAgreementMemberifrs-full:Level3OfFairValueHierarchyMember2020-01-012020-12-310001243429ifrs-full:Level3OfFairValueHierarchyMember2020-01-012020-12-310001243429ifrs-full:WrittenPutOptionsMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-090001243429mt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2020-12-090001243429mt:SpecialPaymentInPelletPurchasesAndSaleAgreementMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-090001243429ifrs-full:Level3OfFairValueHierarchyMember2020-12-090001243429ifrs-full:WrittenPutOptionsMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429mt:SpecialPaymentInPelletPurchasesAndSaleAgreementMemberifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level3OfFairValueHierarchyMember2020-12-310001243429ifrs-full:WrittenPutOptionsMemberifrs-full:Level3OfFairValueHierarchyMember2021-01-012021-12-310001243429mt:SpecialPaymentInPelletPurchasesAndSaleAgreementMemberifrs-full:Level3OfFairValueHierarchyMember2021-01-012021-12-310001243429ifrs-full:Level3OfFairValueHierarchyMember2021-01-012021-12-310001243429ifrs-full:WrittenPutOptionsMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429mt:CallOption1Memberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429mt:SpecialPaymentInPelletPurchasesAndSaleAgreementMemberifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level3OfFairValueHierarchyMember2021-12-310001243429ifrs-full:FixedInterestRateMemberifrs-full:InterestRateRiskMember2021-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:InterestRateRiskMember2021-12-310001243429ifrs-full:TradeReceivablesMembercurrency:USDifrs-full:CurrencyRiskMember2021-12-310001243429currency:USDifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMembercurrency:EUR2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:EURmt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMembercurrency:BRL2021-12-310001243429ifrs-full:CurrencyRiskMembermt:TradePayablesMembercurrency:BRL2021-12-310001243429currency:CADifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMember2021-12-310001243429currency:CADifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMembercurrency:KZTifrs-full:CurrencyRiskMember2021-12-310001243429currency:KZTifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMembercurrency:ZAR2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:ZARmt:TradePayablesMember2021-12-310001243429currency:MXNifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMember2021-12-310001243429currency:MXNifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMembercurrency:UAH2021-12-310001243429ifrs-full:CurrencyRiskMembermt:TradePayablesMembercurrency:UAH2021-12-310001243429ifrs-full:TradeReceivablesMembercurrency:PLNifrs-full:CurrencyRiskMember2021-12-310001243429currency:PLNifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMembercurrency:ARS2021-12-310001243429ifrs-full:CurrencyRiskMembermt:TradePayablesMembercurrency:ARS2021-12-310001243429mt:OtherCurrenciesMemberifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMember2021-12-310001243429mt:OtherCurrenciesMemberifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:TradeReceivablesMemberifrs-full:CurrencyRiskMember2021-12-310001243429ifrs-full:CurrencyRiskMembermt:TradePayablesMember2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:EUR2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:BRL2021-12-310001243429currency:CADifrs-full:CurrencyRiskMember2021-12-310001243429currency:KZTifrs-full:CurrencyRiskMember2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:ZAR2021-12-310001243429currency:MXNifrs-full:CurrencyRiskMember2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:UAH2021-12-310001243429currency:PLNifrs-full:CurrencyRiskMember2021-12-310001243429ifrs-full:CurrencyRiskMembercurrency:ARS2021-12-310001243429ifrs-full:LiquidityRiskMember2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:NotLaterThanOneYearMember2021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:LiquidityRiskMember2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMember2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanFiveYearsMember2021-12-310001243429ifrs-full:LiquidityRiskMembermt:ForeignExchangeContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMembermt:ForeignExchangeContract1Memberifrs-full:NotLaterThanOneYearMember2021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:LiquidityRiskMembermt:ForeignExchangeContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMembermt:ForeignExchangeContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanFiveYearsMembermt:ForeignExchangeContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMembermt:CommodityContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMembermt:CommodityContract1Memberifrs-full:NotLaterThanOneYearMember2021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:LiquidityRiskMembermt:CommodityContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMembermt:CommodityContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanFiveYearsMembermt:CommodityContract1Member2021-12-310001243429ifrs-full:LiquidityRiskMember2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:NotLaterThanOneYearMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:LiquidityRiskMember2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMember2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanFiveYearsMember2020-12-310001243429ifrs-full:LiquidityRiskMembermt:ForeignExchangeContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMembermt:ForeignExchangeContract1Memberifrs-full:NotLaterThanOneYearMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:LiquidityRiskMembermt:ForeignExchangeContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMembermt:ForeignExchangeContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanFiveYearsMembermt:ForeignExchangeContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMembermt:CommodityContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMembermt:CommodityContract1Memberifrs-full:NotLaterThanOneYearMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:LiquidityRiskMembermt:CommodityContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanTwoYearsAndNotLaterThanFiveYearsMembermt:CommodityContract1Member2020-12-310001243429ifrs-full:LiquidityRiskMemberifrs-full:LaterThanFiveYearsMembermt:CommodityContract1Member2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Membermt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:CommodityContract1Memberifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:CommodityContract1Membermt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:EmissionRightsMemberifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:EmissionRightsMembermt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Membermt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:CommodityContract1Memberifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:CommodityContract1Membermt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:EmissionRightsMemberifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:EmissionRightsMembermt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:NotLaterThanThreeMonthsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanThreeMonthsAndNotLaterThanSixMonthsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanSixMonthsAndNotLaterThanOneYearMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:LaterThanTwoYearsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:DerivativeContractEquityMethodInvestmentsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429mt:DerivativeContractEquityMethodInvestmentsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:DerivativeContractEquityMethodInvestmentsMemberifrs-full:CashFlowHedgesMember2019-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMembermt:PrepaymentsAndOtherCurrentAssetsAndAccruedExpensesAndOtherLiabilitiesMember2021-12-310001243429mt:ForeignExchangeContract1Membermt:OtherAssetsAndOtherLongTermObligationsMemberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMembermt:PrepaymentsAndOtherCurrentAssetsAndAccruedExpensesAndOtherLiabilitiesMember2021-12-310001243429mt:OtherAssetsAndOtherLongTermObligationsMemberifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMembermt:PrepaymentsAndOtherCurrentAssetsAndAccruedExpensesAndOtherLiabilitiesMember2021-12-310001243429mt:OtherHedgesMember2021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2021-01-012021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-01-012021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2021-01-012021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2021-12-310001243429ifrs-full:CashFlowHedgesMember2021-01-012021-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMembermt:PrepaymentsAndOtherCurrentAssetsAndAccruedExpensesAndOtherLiabilitiesMember2020-12-310001243429mt:ForeignExchangeContract1Membermt:OtherAssetsAndOtherLongTermObligationsMemberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMembermt:PrepaymentsAndOtherCurrentAssetsAndAccruedExpensesAndOtherLiabilitiesMember2020-12-310001243429mt:OtherAssetsAndOtherLongTermObligationsMemberifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMembermt:PrepaymentsAndOtherCurrentAssetsAndAccruedExpensesAndOtherLiabilitiesMember2020-12-310001243429mt:OtherAssetsAndOtherLongTermObligationsMemberifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-12-310001243429mt:OtherHedgesMember2020-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2019-12-310001243429mt:ForeignExchangeContract1Memberifrs-full:CurrencyRiskMemberifrs-full:CashFlowHedgesMember2020-01-012020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2019-12-310001243429ifrs-full:CommodityPriceRiskMembermt:CommodityContract1Memberifrs-full:CashFlowHedgesMember2020-01-012020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2019-12-310001243429ifrs-full:CommodityPriceRiskMembermt:EmissionRightsMemberifrs-full:CashFlowHedgesMember2020-01-012020-12-310001243429ifrs-full:CashFlowHedgesMember2019-12-310001243429ifrs-full:CashFlowHedgesMember2020-01-012020-12-310001243429mt:CrossCurrencySwap375NotionalAmountMaturityJanuary2016Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429mt:CrossCurrencySwap375NotionalAmountMaturityJanuary2016Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-312021-12-310001243429mt:CrossCurrencySwap500NotionalAmountMaturityMarch2021Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429mt:CrossCurrencySwap500NotionalAmountMaturityMarch2021Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-312021-12-310001243429mt:CrossCurrencySwap500NotionalAmountMaturityJuly2019Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429mt:CrossCurrencySwap500NotionalAmountMaturityJuly2019Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-312021-12-310001243429mt:CrossCurrencySwap100NotionalAmountMaturityJune2018Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429mt:CrossCurrencySwap100NotionalAmountMaturityJune2018Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-312021-12-310001243429mt:CrossCurrencySwap200NotionalAmountMaturityNovember2019Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429mt:CrossCurrencySwap200NotionalAmountMaturityNovember2019Memberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-312021-12-310001243429ifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-312021-12-310001243429mt:CrossCurrencySwap500NotionalAmountMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-03-250001243429mt:CrossCurrencySwap500NotionalAmountMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-03-260001243429mt:CrossCurrencySwap500NotionalAmountMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2015-05-270001243429mt:CrossCurrencySwap500NotionalAmountMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-01-012021-12-310001243429ifrs-full:CurrencyRiskMembermt:CrossCurrencySwapMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429ifrs-full:CurrencyRiskMembermt:CrossCurrencySwapMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-01-012021-12-310001243429mt:EURDebtMemberifrs-full:CurrencyRiskMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-12-310001243429mt:EURDebtMemberifrs-full:CurrencyRiskMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2021-01-012021-12-310001243429ifrs-full:CurrencyRiskMembermt:CrossCurrencySwap2018TotalMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-12-310001243429ifrs-full:CurrencyRiskMembermt:CrossCurrencySwap2018TotalMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-01-012020-12-310001243429mt:EURDebtMemberifrs-full:CurrencyRiskMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-12-310001243429mt:EURDebtMemberifrs-full:CurrencyRiskMemberifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-01-012020-12-310001243429ifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-12-310001243429ifrs-full:HedgesOfNetInvestmentInForeignOperationsMember2020-01-012020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:BaseMetalsMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:BaseMetalsMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:FreightMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:FreightMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:EnergyOilGasElectricityMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:EnergyOilGasElectricityMember2020-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:EmissionRightsMember2021-12-310001243429ifrs-full:Level2OfFairValueHierarchyMembermt:EmissionRightsMember2020-12-310001243429mt:EmissionRightsMember2021-12-310001243429mt:EmissionRightsMember2020-12-310001243429ifrs-full:CurrencyRiskMember2021-01-012021-12-310001243429ifrs-full:CurrencyRiskMember2020-01-012020-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:InterestRateRiskMember2021-01-012021-12-310001243429ifrs-full:FloatingInterestRateMemberifrs-full:InterestRateRiskMember2020-01-012020-12-310001243429ifrs-full:InterestRateRiskMember2021-01-012021-12-310001243429ifrs-full:CommodityPriceRiskMember2021-01-012021-12-310001243429mt:BaseMetalsMemberifrs-full:CommodityPriceRiskMember2021-01-012021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:IronOreMember2021-01-012021-12-310001243429ifrs-full:CommodityPriceRiskMembermt:FreightMember2021-01-012021-12-310001243429mt:EmissionRightsMemberifrs-full:CommodityPriceRiskMember2021-01-012021-12-310001243429mt:EnergyMemberifrs-full:CommodityPriceRiskMember2021-01-012021-12-310001243429ifrs-full:CommodityPriceRiskMember2020-01-012020-12-310001243429mt:BaseMetalsMemberifrs-full:CommodityPriceRiskMember2020-01-012020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:IronOreMember2020-01-012020-12-310001243429ifrs-full:CommodityPriceRiskMembermt:FreightMember2020-01-012020-12-310001243429mt:EmissionRightsMemberifrs-full:CommodityPriceRiskMember2020-01-012020-12-310001243429mt:EnergyMemberifrs-full:CommodityPriceRiskMember2020-01-012020-12-310001243429ifrs-full:LandAndBuildingsMember2021-12-310001243429ifrs-full:LandAndBuildingsMember2020-12-310001243429mt:MachineryEquipmentAndOtherMember2021-12-310001243429mt:MachineryEquipmentAndOtherMember2020-12-310001243429ifrs-full:LandAndBuildingsMember2021-01-012021-12-310001243429ifrs-full:LandAndBuildingsMember2020-01-012020-12-310001243429mt:MachineryEquipmentAndOtherMember2021-01-012021-12-310001243429mt:MachineryEquipmentAndOtherMember2020-01-012020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanThreeYearsMember2021-12-310001243429ifrs-full:LaterThanThreeYearsAndNotLaterThanFiveYearsMember2021-12-310001243429ifrs-full:NotLaterThanOneYearMember2020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanThreeYearsMember2020-12-310001243429ifrs-full:LaterThanThreeYearsAndNotLaterThanFiveYearsMember2020-12-310001243429ifrs-full:LaterThanFiveYearsMember2020-12-310001243429ifrs-full:NotLaterThanOneYearMember2021-01-012021-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanThreeYearsMember2021-01-012021-12-310001243429ifrs-full:LaterThanThreeYearsAndNotLaterThanFiveYearsMember2021-01-012021-12-310001243429ifrs-full:LaterThanFiveYearsMember2021-01-012021-12-310001243429ifrs-full:NotLaterThanOneYearMember2020-01-012020-12-310001243429ifrs-full:LaterThanOneYearAndNotLaterThanThreeYearsMember2020-01-012020-12-310001243429ifrs-full:LaterThanThreeYearsAndNotLaterThanFiveYearsMember2020-01-012020-12-310001243429ifrs-full:LaterThanFiveYearsMember2020-01-012020-12-31mt:employee0001243429ifrs-full:PensionDefinedBenefitPlansMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMember2020-12-310001243429mt:TerminationBenefitsMember2021-12-310001243429mt:TerminationBenefitsMember2020-12-310001243429mt:PensionPlanOtherPostemploymentAndTerminationBenefitPlansMember2021-12-310001243429mt:PensionPlanOtherPostemploymentAndTerminationBenefitPlansMember2020-12-310001243429mt:SocialPlanProvisionMember2021-12-310001243429mt:SocialPlanProvisionMember2020-12-310001243429mt:SocialPlanProvisionMembercountry:ES2021-12-310001243429mt:ArcelorMittalUSALLCMembermt:OtherPostEmploymentBenefitPlanMember2020-12-092020-12-090001243429mt:CollectiveLaborAgreementMembercountry:CA2014-07-012014-09-300001243429mt:CollectiveLaborAgreementMembercountry:CA2020-07-012020-09-300001243429mt:CollectiveLaborAgreementMembercountry:CA2016-02-012016-02-280001243429mt:FullyFundedPensionPlansMembercountry:CA2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PresentValueOfDefinedBenefitObligationMember2019-01-012019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PlanAssetsMember2019-01-012019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BR2019-01-012019-12-310001243429country:BE2015-12-012015-12-310001243429country:BE2016-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:US2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:CA2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PlanAssetsMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PlanAssetsMember2020-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:US2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:CA2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PlanAssetsMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PlanAssetsMember2021-01-012021-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:US2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:CA2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PlanAssetsMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PlanAssetsMember2021-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:US2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:CA2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BR2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Member2021-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:US2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:CA2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BR2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Member2020-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:US2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:CA2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BR2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Member2021-01-012021-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:US2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:CA2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PlanAssetsMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PlanAssetsMember2019-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:US2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMembercountry:CA2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BRifrs-full:PlanAssetsMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Memberifrs-full:PlanAssetsMember2020-01-012020-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMemberifrs-full:PlanAssetsMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:US2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:CA2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BR2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Member2019-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:US2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:CA2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:BR2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Member2020-01-012020-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMember2020-01-012020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMember2019-01-012019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:US2019-01-012019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembercountry:CA2019-01-012019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMembermt:Europe1Member2019-01-012019-12-310001243429mt:OtherRegionsMemberifrs-full:PensionDefinedBenefitPlansMember2019-01-012019-12-310001243429country:PLmt:OtherPostEmploymentBenefitPlanMember2021-04-012021-04-300001243429country:PLmt:OtherPostEmploymentBenefitPlanMember2021-06-012021-06-300001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:US2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:CA2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PlanAssetsMember2020-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:US2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:CA2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PlanAssetsMember2021-01-012021-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:US2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:CA2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PlanAssetsMember2021-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:US2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:CA2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Member2021-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:USifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMembercountry:CA2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PresentValueOfDefinedBenefitObligationMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:US2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:CA2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PlanAssetsMember2019-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:US2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMembercountry:CA2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Memberifrs-full:PlanAssetsMember2020-01-012020-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMemberifrs-full:PlanAssetsMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:US2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:CA2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Member2020-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:US2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:CA2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Member2021-01-012021-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:US2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:CA2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Member2020-01-012020-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMember2020-01-012020-12-310001243429mt:OtherPostEmploymentBenefitPlanMember2019-01-012019-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:US2019-01-012019-12-310001243429mt:OtherPostEmploymentBenefitPlanMembercountry:CA2019-01-012019-12-310001243429mt:OtherPostEmploymentBenefitPlanMembermt:Europe1Member2019-01-012019-12-310001243429mt:OtherRegionsMembermt:OtherPostEmploymentBenefitPlanMember2019-01-012019-12-310001243429ifrs-full:CostOfSalesMember2021-01-012021-12-310001243429ifrs-full:CostOfSalesMember2020-01-012020-12-310001243429ifrs-full:CostOfSalesMember2019-01-012019-12-310001243429ifrs-full:SellingGeneralAndAdministrativeExpenseMember2021-01-012021-12-310001243429ifrs-full:SellingGeneralAndAdministrativeExpenseMember2020-01-012020-12-310001243429ifrs-full:SellingGeneralAndAdministrativeExpenseMember2019-01-012019-12-310001243429mt:FinancingCostsMember2021-01-012021-12-310001243429mt:FinancingCostsMember2020-01-012020-12-310001243429mt:FinancingCostsMember2019-01-012019-12-310001243429mt:Europe1Member2021-12-310001243429ifrs-full:Level1OfFairValueHierarchyMembercountry:CA2021-12-310001243429country:BRifrs-full:Level1OfFairValueHierarchyMember2021-12-310001243429ifrs-full:Level1OfFairValueHierarchyMembermt:Europe1Member2021-12-310001243429ifrs-full:Level2And3OfFairValueHierarchyMembercountry:CA2021-12-310001243429ifrs-full:Level2And3OfFairValueHierarchyMembercountry:BR2021-12-310001243429ifrs-full:Level2And3OfFairValueHierarchyMembermt:Europe1Member2021-12-310001243429mt:Europe1Member2020-12-310001243429ifrs-full:Level1OfFairValueHierarchyMembercountry:CA2020-12-310001243429country:BRifrs-full:Level1OfFairValueHierarchyMember2020-12-310001243429ifrs-full:Level1OfFairValueHierarchyMembermt:Europe1Member2020-12-310001243429ifrs-full:Level2And3OfFairValueHierarchyMembercountry:CA2020-12-310001243429ifrs-full:Level2And3OfFairValueHierarchyMembercountry:BR2020-12-310001243429ifrs-full:Level2And3OfFairValueHierarchyMembermt:Europe1Member2020-12-310001243429ifrs-full:BottomOfRangeMemberifrs-full:PensionDefinedBenefitPlansMember2021-12-310001243429ifrs-full:TopOfRangeMemberifrs-full:PensionDefinedBenefitPlansMember2021-12-310001243429ifrs-full:BottomOfRangeMemberifrs-full:PensionDefinedBenefitPlansMember2020-12-310001243429ifrs-full:TopOfRangeMemberifrs-full:PensionDefinedBenefitPlansMember2020-12-310001243429ifrs-full:BottomOfRangeMemberifrs-full:PensionDefinedBenefitPlansMember2019-12-310001243429ifrs-full:TopOfRangeMemberifrs-full:PensionDefinedBenefitPlansMember2019-12-310001243429ifrs-full:BottomOfRangeMembermt:OtherPostEmploymentBenefitPlanMember2021-12-310001243429ifrs-full:TopOfRangeMembermt:OtherPostEmploymentBenefitPlanMember2021-12-310001243429ifrs-full:BottomOfRangeMembermt:OtherPostEmploymentBenefitPlanMember2020-12-310001243429ifrs-full:TopOfRangeMembermt:OtherPostEmploymentBenefitPlanMember2020-12-310001243429ifrs-full:BottomOfRangeMembermt:OtherPostEmploymentBenefitPlanMember2019-12-310001243429ifrs-full:TopOfRangeMembermt:OtherPostEmploymentBenefitPlanMember2019-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:WeightedAverageMember2021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:WeightedAverageMember2020-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:WeightedAverageMember2019-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:WeightedAverageMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:WeightedAverageMember2020-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:WeightedAverageMember2019-12-310001243429ifrs-full:ActuarialAssumptionOfDiscountRatesMemberifrs-full:PensionDefinedBenefitPlansMember2021-12-310001243429ifrs-full:ActuarialAssumptionOfDiscountRatesMemberifrs-full:PensionDefinedBenefitPlansMember2021-01-012021-12-310001243429ifrs-full:ActuarialAssumptionOfExpectedRatesOfSalaryIncreasesMemberifrs-full:PensionDefinedBenefitPlansMember2021-12-310001243429ifrs-full:ActuarialAssumptionOfExpectedRatesOfSalaryIncreasesMemberifrs-full:PensionDefinedBenefitPlansMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:ActuarialAssumptionOfMortalityRatesMember2021-01-012021-12-310001243429ifrs-full:PensionDefinedBenefitPlansMemberifrs-full:ActuarialAssumptionOfMortalityRatesMember2021-12-310001243429ifrs-full:ActuarialAssumptionOfDiscountRatesMembermt:OtherPostEmploymentBenefitPlanMember2021-12-310001243429ifrs-full:ActuarialAssumptionOfDiscountRatesMembermt:OtherPostEmploymentBenefitPlanMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:ActuarialAssumptionOfMedicalCostTrendRatesMember2021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:ActuarialAssumptionOfMedicalCostTrendRatesMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:ActuarialAssumptionOfMortalityRatesMember2021-01-012021-12-310001243429mt:OtherPostEmploymentBenefitPlanMemberifrs-full:ActuarialAssumptionOfMortalityRatesMember2021-12-310001243429mt:ProForma1Membermt:ArcelorMittalGlobalStockOption20092018Member2021-12-310001243429ifrs-full:TopOfRangeMembermt:ArcelorMittalGlobalStockOption20092018Membermt:EmployeeStockOption1Member2021-01-012021-12-3100012434292010-08-012010-08-310001243429ifrs-full:BottomOfRangeMember2018-12-310001243429ifrs-full:TopOfRangeMember2018-12-310001243429ifrs-full:BottomOfRangeMember2019-01-012019-12-310001243429ifrs-full:TopOfRangeMember2019-01-012019-12-310001243429ifrs-full:BottomOfRangeMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ArcelorMittalEquityIncentivePlanMember2021-01-012021-12-310001243429mt:ArcelorMittalEquityIncentivePlanMembermt:RestrictedShareUnitsRSUMember2021-01-012021-12-310001243429mt:RestrictedShareUnitsRSUAndPerformanceShareUnitsPSUMemberifrs-full:TopOfRangeMembermt:ExecutiveOfficePlanMember2019-05-070001243429mt:RestrictedShareUnitsRSUAndPerformanceShareUnitsPSUMemberifrs-full:TopOfRangeMembermt:ExecutiveOfficePlanMember2020-06-130001243429mt:RestrictedShareUnitsRSUAndPerformanceShareUnitsPSUMemberifrs-full:TopOfRangeMembermt:ExecutiveOfficePlanMember2021-06-080001243429mt:ArcelorMittalEquityIncentivePlanMembermt:SpecialGrantMembermt:RestrictedShareUnitsRSUMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ChiefExecutiveOfficer1Membermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveCharimanMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMembermt:VestingBasedOnTSRComparedToPeerGroupMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMembermt:VestingBasedOnEPSComparedToPeerGroupMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnTSRComparedToPeerGroupMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnTSRComparedToPeerGroupStretchLevelMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnGapToCompetitionMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedonGapToCompetitionTargetLevelMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnGapToCompetitionStretchLevelMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnESGMembermt:ExecutiveOfficePlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMembermt:VestingBasedOnESGTargetLevelMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnESGMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnESGTargetLevelMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnESGStretchLevelMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:RestrictedShareUnitsRSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnVestingPeriodPeriodOneMember2021-01-012021-12-310001243429mt:VestingBasedOnVestingPeriodPeriodTwoMembermt:RestrictedShareUnitsRSUMembermt:ExecutiveOfficersPlanMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:VestingBasedOnVestingPeriodPeriodOneMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnVestingPeriodPeriodOneMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:VestingBasedOnVestingPeriodPeriodTwoMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnVestingPeriodPeriodTwoMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:PerformanceBasedOnTSRComparedToPerformanceIndexMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:PerformanceBasedOnEPSComparedToPeerGroupMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ChiefExecutiveOfficer1Membermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveCharimanMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexTargetLevelMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexThresholdLevelMembermt:ExecutiveOfficePlanMember2016-01-012016-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ChiefExecutiveOfficer1Membermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveCharimanMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnPerformanceOfROCETargetLevelMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexTargetLevelMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedonGapToCompetitionTargetLevelMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexThresholdLevelMembermt:ExecutiveOfficePlanMember2018-01-012018-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveCharimanMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ChiefExecutiveOfficer1Membermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnPerformanceOfROCETargetLevelMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexTargetLevelMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedonGapToCompetitionTargetLevelMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexThresholdLevelMembermt:ExecutiveOfficePlanMember2019-01-012019-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveCharimanMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ChiefExecutiveOfficer1Membermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupThresholdLevelMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonEPSComparedToPeerGroupTargetLevelMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexTargetLevelMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedonGapToCompetitionTargetLevelMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedonTSRComparedToPerformanceIndexThresholdLevelMembermt:ExecutiveOfficePlanMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMembermt:VestingBasedOnGapToCompetitionThresholdLevelMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:RestrictedShareUnitsRSUMembermt:ExecutiveOfficersPlanMembermt:VestingBasedOnVestingPeriodPeriodOneMember2020-01-012020-12-310001243429mt:VestingBasedOnVestingPeriodPeriodTwoMembermt:RestrictedShareUnitsRSUMembermt:ExecutiveOfficersPlanMember2020-01-012020-12-310001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateDecember162021MaturityDueDecember2024Member2021-12-162021-12-16mt:beneficiary0001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateDecember162021MaturityDueDecember2024Member2021-12-310001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateDecember162021MaturityDueDecember2024Member2021-12-312021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember162021MaturityDueJanuary2025Member2021-12-162021-12-160001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember162021MaturityDueJanuary2025Member2021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember162021MaturityDueJanuary2025Member2021-12-312021-12-310001243429mt:GrantDateDecember162021MaturityDueJanuary2025Membermt:ExecutiveOfficePlanMember2021-12-162021-12-160001243429mt:GrantDateDecember162021MaturityDueJanuary2025Membermt:ExecutiveOfficePlanMember2021-12-310001243429mt:GrantDateDecember162021MaturityDueJanuary2025Membermt:ExecutiveOfficePlanMember2021-12-312021-12-310001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateMay72021MaturityDueMay2023Member2021-05-072021-05-070001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateMay72021MaturityDueMay2023Member2021-12-310001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateMay72021MaturityDueMay2023Member2021-12-312021-12-310001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateDecember142020MaturityDueDecember2023Member2020-12-142020-12-140001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateDecember142020MaturityDueDecember2023Member2021-12-310001243429mt:RestrictedShareUnitsRSUMembermt:GrantDateDecember142020MaturityDueDecember2023Member2021-12-312021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember142020MaturityDueJanuary12024Member2020-12-142020-12-140001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember142020MaturityDueJanuary12024Member2021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember142020MaturityDueJanuary12024Member2021-12-312021-12-310001243429mt:ExecutiveOfficePlanMembermt:GrantDateDecember142020MaturityDueJanuary12024Member2020-12-142020-12-140001243429mt:ExecutiveOfficePlanMembermt:GrantDateDecember142020MaturityDueJanuary12024Member2021-12-310001243429mt:ExecutiveOfficePlanMembermt:GrantDateDecember142020MaturityDueJanuary12024Member2021-12-312021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantdateDecember162019MaturitydueJanuary12023Member2019-12-162019-12-160001243429mt:PerformanceShareUnitsPSUMembermt:GrantdateDecember162019MaturitydueJanuary12023Member2021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantdateDecember162019MaturitydueJanuary12023Member2021-12-312021-12-310001243429mt:GrantdateDecember162019MaturitydueJanuary12023Membermt:ExecutiveOfficePlanMember2019-12-162019-12-160001243429mt:GrantdateDecember162019MaturitydueJanuary12023Membermt:ExecutiveOfficePlanMember2021-12-310001243429mt:GrantdateDecember162019MaturitydueJanuary12023Membermt:ExecutiveOfficePlanMember2021-12-312021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantdateDecember202018MaturitydueJanuary12022Member2018-12-202018-12-200001243429mt:PerformanceShareUnitsPSUMembermt:GrantdateDecember202018MaturitydueJanuary12022Member2021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantdateDecember202018MaturitydueJanuary12022Member2021-12-312021-12-310001243429mt:GrantdateDecember202018MaturitydueJanuary12022Membermt:ExecutiveOfficePlanMember2018-12-202018-12-200001243429mt:GrantdateDecember202018MaturitydueJanuary12022Membermt:ExecutiveOfficePlanMember2021-12-310001243429mt:GrantdateDecember202018MaturitydueJanuary12022Membermt:ExecutiveOfficePlanMember2021-12-312021-12-310001243429mt:GrantdateJune302016MaturitydueJanuary12022Membermt:ExecutiveOfficePlanMember2016-06-302016-06-300001243429mt:GrantdateJune302016MaturitydueJanuary12022Membermt:ExecutiveOfficePlanMember2021-12-310001243429mt:GrantdateJune302016MaturitydueJanuary12022Membermt:ExecutiveOfficePlanMember2021-12-312021-12-3100012434292016-07-012021-12-310001243429ifrs-full:BottomOfRangeMember2016-07-012021-12-310001243429ifrs-full:TopOfRangeMember2016-07-012021-12-3100012434292021-12-312021-12-310001243429mt:PerformanceShareUnitsPSUMember2021-01-012021-12-310001243429mt:PerformanceShareUnitsPSUMember2020-01-012020-12-310001243429mt:PerformanceShareUnitsPSUMember2019-01-012019-12-310001243429mt:RestrictedShareUnitsRSUMember2018-12-310001243429mt:PerformanceShareUnitsPSUMember2018-12-310001243429mt:RestrictedShareUnitsRSUMember2019-01-012019-12-310001243429mt:RestrictedShareUnitsRSUMember2019-12-310001243429mt:PerformanceShareUnitsPSUMember2019-12-310001243429mt:RestrictedShareUnitsRSUMember2020-01-012020-12-310001243429mt:RestrictedShareUnitsRSUMember2020-12-310001243429mt:PerformanceShareUnitsPSUMember2020-12-310001243429mt:RestrictedShareUnitsRSUMember2021-01-012021-12-310001243429mt:RestrictedShareUnitsRSUMember2021-12-310001243429mt:PerformanceShareUnitsPSUMember2021-12-310001243429mt:PerformanceShareUnitsPSUMembermt:GrantDateDecember182015Member2019-01-012019-12-310001243429ifrs-full:OtherEnvironmentRelatedProvisionMember2020-12-310001243429ifrs-full:OtherEnvironmentRelatedProvisionMember2021-01-012021-12-310001243429ifrs-full:OtherEnvironmentRelatedProvisionMember2021-12-310001243429mt:EmissionRightsMember2020-12-310001243429mt:EmissionRightsMember2021-01-012021-12-310001243429mt:EmissionRightsMember2021-12-310001243429mt:AssetRetirementObligationsMember2020-12-310001243429mt:AssetRetirementObligationsMember2021-01-012021-12-310001243429mt:AssetRetirementObligationsMember2021-12-310001243429ifrs-full:ProvisionForDecommissioningRestorationAndRehabilitationCostsMember2020-12-310001243429ifrs-full:ProvisionForDecommissioningRestorationAndRehabilitationCostsMember2021-01-012021-12-310001243429ifrs-full:ProvisionForDecommissioningRestorationAndRehabilitationCostsMember2021-12-310001243429mt:StaffRelatedObligationsMember2020-12-310001243429mt:StaffRelatedObligationsMember2021-01-012021-12-310001243429mt:StaffRelatedObligationsMember2021-12-310001243429mt:VoluntarySeparationPlansMember2020-12-310001243429mt:VoluntarySeparationPlansMember2021-01-012021-12-310001243429mt:VoluntarySeparationPlansMember2021-12-310001243429ifrs-full:LegalProceedingsProvisionMember2020-12-310001243429ifrs-full:LegalProceedingsProvisionMember2021-01-012021-12-310001243429ifrs-full:LegalProceedingsProvisionMember2021-12-310001243429ifrs-full:ProvisionForTaxesOtherThanIncomeTaxMember2020-12-310001243429ifrs-full:ProvisionForTaxesOtherThanIncomeTaxMember2021-01-012021-12-310001243429ifrs-full:ProvisionForTaxesOtherThanIncomeTaxMember2021-12-310001243429mt:OtherLegalClaimsMember2020-12-310001243429mt:OtherLegalClaimsMember2021-01-012021-12-310001243429mt:OtherLegalClaimsMember2021-12-310001243429ifrs-full:OnerousContractsProvisionMember2020-12-310001243429ifrs-full:OnerousContractsProvisionMember2021-01-012021-12-310001243429ifrs-full:OnerousContractsProvisionMember2021-12-310001243429ifrs-full:MiscellaneousOtherProvisionsMember2020-12-310001243429ifrs-full:MiscellaneousOtherProvisionsMember2021-01-012021-12-310001243