The total heat capacity, C, of a system is used to correlate the change in heat, ΔH, of a system to the observed change in temperature, ΔT:

ΔH = CΔT

For aconstant volumecalorimeter, the total heat capacity is the sum of the heat capacity of the calorimeter, c_cal, and thespecific heat capacityof water, c_water, times the mass of water in the water bath, m_water:

C = c_cal+ c_waterm_water

The heat capacity of the calorimeter itself is usually found experimentally by combusting a sample with a known heat of combustion, and using the observed change in temperature to calculate c_cal.

For aconstant pressure calorimeter的总热容specific heat capacityof the solvent (typically water) times the mass of that solvent:

C = c_solventm_solvent