Heat transfer formula
This is the sensible-heat equation: the energy needed to change the temperature of a mass equals the mass times its specific heat times the temperature change. It is the workhorse of heating, cooling, and energy calculations.
Variables
| Q | Heat energy | J |
| m | Mass | kg |
| c | Specific heat capacity | J/kg·K |
| ΔT | Temperature change | K or °C |
Rearranged
m = Q / (c × ΔT)
Worked example
Heating 2 kg of water (c = 4186) by 30 degrees.
Multiply through: 2 × 4186 × 30 = 251,160 J.
This covers sensible heat, where temperature changes but the material stays in one phase. Melting or boiling needs latent heat instead, which happens at constant temperature. The specific heat value sets how much energy each material soaks up per degree.
Need specific heat values?
See the Specific Heat Capacity Table for common materials.
Sensible vs latent heat
Sensible heat changes a material temperature and follows mass times specific heat times temperature change. Latent heat changes its phase, melting or boiling, at a constant temperature and uses a different property, the latent heat of fusion or vaporization. A full heating calculation that crosses a phase change adds both contributions together.
Using specific heat
Specific heat is the energy to raise one kilogram by one degree, and it varies widely: water is high, metals are low. That is why a metal pan heats quickly while the water in it takes much longer. Picking the right specific heat for each material is the key to an accurate heat calculation.
FAQ
What is the heat transfer formula?
For a temperature change, heat equals mass times specific heat times the temperature change, Q = m c delta T.
What is the difference between sensible and latent heat?
Sensible heat changes temperature; latent heat changes phase at constant temperature. The mcDeltaT formula covers only sensible heat.
How do I find specific heat values?
Use a specific heat table. Water is about 4186 J/kg-K, while most metals are far lower, around a tenth of that.