J/KtomJ/K

1 J/K equals 1000 mJ/K. To convert, multiply the value in joules per kelvin by 1000.

1 J/K = 1000 mJ/K. For any value, multiply by 1000.

Divide by the same factor — or equivalently, multiply by 0.001. So 1 mJ/K = 0.001 J/K.

Thermal-capacity conversions between J/K and mJ/K appear in thermal-mass analysis of bodies, calorimetry, R-C thermal-network modelling, electronics thermal capacitance and large-equipment thermal-storage sizing. J/K and kJ/K are the SI standard; MJ/K and kWh/K cover large-equipment and building thermal-mass notation; BTU/°F is the US convention; cal/K and kcal/K are common in chemistry and thermochemistry. This category is lumped heat capacity only — it does NOT include specific heat capacity (J/(kg·K), requires mass), molar heat capacity (J/(mol·K), requires molecular weight) or volumetric heat capacity, all of which are different physical quantities.

The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).