The formula
Q = m · c · ΔT
| Symbol | Quantity | Unit |
|---|---|---|
| Q | Heat | J |
| m | Mass | kg |
| c | Specific heat capacity | J/(kg·K) |
| ΔT | Change in temperature | K |
What it means
Specific heat capacity is how much energy it takes to raise one kilogram by one degree. It varies enormously between materials, and water's is unusually high.
How to work it out by hand
- Multiply the mass by the specific heat capacity
- Multiply by the temperature change
- The answer is in joules
What is worth knowing
Water's specific heat, 4186 J/(kg·K), is among the highest of any common substance, and that single number shapes the planet: oceans absorb and release vast amounts of heat with small temperature swings, which is why coastal climates are mild and inland ones extreme. It is also why water is the standard coolant. Note that this formula covers temperature change only — a phase change absorbs energy at constant temperature, which is latent heat and a separate calculation entirely. Melting ice at 0 °C takes 334 kJ/kg without the thermometer moving at all.