Alternative　low-carbon　cements　could　contribute　significantly　to　CO2　reduction　in　the　cement　industry.　However,　the　existing　methods　require　the　input　of　the　actual　production　data,　and　thus　cannot　be　used　to　calculate　CO2　emissions　of　alternative　low-carbon　cements　that　are　not　yet　produced　in　cement　plants.　This　study　aims　to　develop　a　model　to　analyze　the　theoretical　CO2　emissions　of　alternative　low-carbon　cements.　The　novelty　of　this　model　is　that　it　can　be　used　to　calculate　the　fuel　consumed　in　the　production　of　new　low-carbon　cements　based　on　the　theory　of　heat　balance,　and　then　predict　their　CO2　emissions.　The　model　is　used　to　calculate　CO2　emissions　of　several　low-carbon　binders　and　ordinary　Portland　cement　(OPC).　The　results　show　that　the　direct　CO2　emissions　of　OPC　clinker　calculated　by　this　model　approach　the　value　derived　from　the　cement　plants　and　the　Cement　Sustainability　and　Initiative　(CSI).　Calcium　sulfoaluminate　(CSA)　clinker　has　the　direct　CO2　emissions　of　0.540　kg/kg,　34%　lower　than　OPC　clinker,　while　its　cost　of　raw　materials　is　over　four　times　that　of　OPC　clinker.　High-belite　calcium　sulfoaluminate　(HB-CSA)　clinker,　with　the　direct　CO2　emissions　comparable　to　CSA　clinker,　lowers　its　cost　of　raw　materials　by　half　as　it　requires　less　expensive　bauxite.　Moreover,　CO2　emissions　from　HB-CSA　cement　production　can　be　further　reduced　by　the　use　of　high　volume　of　supplementary　cementitious　materials　(SCMs).　The　knowledge　gained　provides　a　valuable　reference　for　the　design　of　new　low-carbon　binders.　©　2021　Elsevier　Ltd