What this calculator finds

Enter the mass, specific heat capacity, and temperature change of a substance to calculate the required heat energy in various units (J, kJ, kcal, BTU).

Why it matters

• Essential for determining capacity of heating/cooling equipment (heaters, coolers, boilers, etc.)
• Key item in energy balance for process heat calculations
• Used for predicting cooling time and thermal management design

Heat Capacity Formula

The fundamental heat transfer formula is Q = m × c × ΔT, representing the heat energy required for a temperature change.

Common specific heat capacity values (at room temperature)

• Water: 4.186 kJ/(kg·K) = 1.000 kcal/(kg·°C)
• Aluminum: 0.897 kJ/(kg·K)
• Copper: 0.385 kJ/(kg·K)
• Steel: 0.490 kJ/(kg·K)
• Air: 1.005 kJ/(kg·K)

Unit conversion

• 1 kJ = 0.239 kcal = 0.9478 BTU
• 1 kcal = 4.186 kJ = 3.968 BTU
• 1 BTU = 1.055 kJ = 0.252 kcal

Practical tips

• Water's high specific heat capacity makes it an effective cooling medium
• Specific heat capacity changes with temperature; use average values for wide temperature ranges
• When phase changes (evaporation, solidification) occur, latent heat must be added separately

Limitations & cautions

• Specific heat capacity varies with temperature/pressure; note these are near-room-temperature approximations
• For gases, specific heat at constant pressure (Cp) and constant volume (Cv) differ; select the appropriate value
• Mixture heat capacity varies with composition; experimental measurement is recommended