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Specific Heat (Q = mcΔT) Calculator

Calculate the heat energy needed to raise or lower a substance's temperature from its mass, specific heat capacity, and temperature change — in joules, kJ, kWh, and kcal.

Heat energy
41,860 J
In kilojoules
41.86 kJ
In kilowatt-hours
0.0116 kWh
In kilocalories (food Calories)
10 kcal

How it works

Heat energy follows Q = m × c × ΔT: mass times specific heat capacity times the temperature change. Specific heat capacity is a material property (how much energy it takes to change 1 kg of that substance by 1°C) that you look up and enter — water is about 4186 J/(kg·K), aluminum about 897, so the same temperature change takes far more energy for water than for metal.

Mass and the temperature change both convert cleanly between metric and imperial using the page's unit toggle (1 kg = 2.20462 lbs; a 1°C change equals 1.8°F of change) — but specific heat capacity itself stays in one SI unit, since it's a constant you'd look up in a table rather than a measurement you take, the same way this site leaves a spring constant or electrical resistivity untouched by the toggle.

The result is shown in joules (the SI base unit), kilojoules, kilowatt-hours (useful for comparing to an electricity bill), and kilocalories — the 'Calories' used on food labels, which are actually kilocalories.

FAQ

Why does the temperature input convert between °C and °F with a simple multiply, when converting an actual temperature needs an offset too?

Because this field is a temperature CHANGE (a ΔT), not an absolute reading. Converting an absolute temperature needs an offset (°F = °C × 1.8 + 32) since the two scales have different zero points, but a difference between two temperatures doesn't — the offset cancels out, so 1 Celsius degree of change is simply 1.8 Fahrenheit degrees of change.

Can this calculator account for a phase change, like boiling or melting?

No — Q = mcΔT only applies within a single phase (e.g. heating liquid water). Boiling or melting absorbs or releases additional energy (latent heat) at a constant temperature, which this formula doesn't include.

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