Calculate heat energy (Q), mass (m), specific heat capacity (c), or temperature change (ΔT) using the formula Q = mcΔT. Choose what you want to solve for, enter the three known values, and get your result instantly. Works with common units including joules, kilojoules, calories, grams, and kilograms. Also try the Ideal Gas Law Calculator.
Result
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Unit
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Formula Used
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Heat Energy (J)
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Mass (kg)
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Temperature Change (K)
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Specific Heat (J/kg·K)
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Specific heat capacity is the amount of thermal energy required to raise the temperature of 1 kg (or 1 g, depending on units) of a substance by 1 K (or 1°C). It is a physical property unique to each material — for example, water has a specific heat of 4,184 J/kg·K, meaning it takes a lot of energy to heat compared to metals. See also our Solved Variable (Result) — Combined Gas Law.
The formula is Q = m × c × ΔT, where Q is the heat energy transferred (in joules), m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature. You can rearrange this to solve for any one variable if the other three are known.
The SI unit is J/kg·K (joules per kilogram per kelvin). Other common units include J/g·K, cal/g·°C, kJ/kg·K, and BTU/lb·°F. Since a change of 1°C equals a change of 1 K, J/g·K and J/g·°C are numerically equivalent.
Water has one of the highest specific heat capacities of any common substance: approximately 4,184 J/kg·K (or 4.184 J/g·K). This means water can absorb a large amount of heat before its temperature rises significantly, making it excellent for cooling systems and climate regulation. You might also find our use the Enthalpy Calculator (Hess's Law) useful.
Aluminum has a specific heat capacity of approximately 897 J/kg·K (0.897 J/g·K), while copper has approximately 385 J/kg·K (0.385 J/g·K). Both are much lower than water, which is why metals heat up and cool down much faster.
A negative Q value means that the substance is releasing heat — it is cooling down. A positive Q value means the substance is absorbing heat and warming up. The sign of ΔT (final temperature minus initial temperature) determines the sign of Q.
Specific heat at constant volume (Cv) is measured when the volume of the substance is held fixed during heating, so no work is done by expansion. This differs from specific heat at constant pressure (Cp), which allows volume to change. For solids and liquids the difference is negligible, but for gases it is significant.
Yes — a temperature change of 1°C is numerically identical to a change of 1 K, because the two scales have the same interval size. So ΔT in °C = ΔT in K. However, a change in °F is different: ΔT(K) = ΔT(°F) × 5/9. Check out our Sensible Heat Calculator as well.