Specific Heat Calculator:
q = mcΔT calorimetry.

Field guide

Specific heat, in plain terms.

Specific heat capacity tells you how stubbornly a substance resists changing temperature. Pour a kilojoule of energy into a kilogram of water and the temperature creeps up by about a quarter of a degree; pour the same kilojoule into a kilogram of copper and it jumps by nearly three degrees. That difference is the substance's specific heat, c, in joules per gram per degree Celsius.

The equation

The sensible-heat equation ties together how much energy is involved, how much substance there is, what it's made of, and how much its temperature changes:

Rearrange to solve for whichever quantity you don't know:

The calculator above does this with a click — switch the “Solve for” toggle to the unknown and the matching field becomes the result.

Intensive vs extensive — and the difference between c and C

Specific heat capacity c is an intensive property — it depends only on what the substance is, not how much you have. Heat capacity C, on the other hand, is extensive: it scales with the size of the object:

So a small cup of water and a swimming pool both have c = 4.184 J/g·°C, but the pool has an enormously larger C. When chemists say “specific heat” without qualifiers they almost always mean the intensive c, which is what this calculator uses.

Sensible heat vs latent heat

The q = mcΔT equation only describes sensible heat — the heat that changes the temperature of a substance. Real heating curves also include latent heat, the energy absorbed or released during a phase change without any temperature change at all. For example, melting 1 g of ice at 0 °C absorbs about 334 J without raising the temperature one degree:

where L is the heat of fusion or vaporisation. If your problem straddles a phase boundary, split it into pieces: heat the solid up to the melting point with mcΔT, melt it with mL, then heat the liquid with mcΔT again. The calculator flags water problems that cross 0 °C or 100 °C precisely because of this.

Worked example — warm a pot of water

How much energy does it take to heat 200 g of water from 20 °C to 80 °C?

• m = 200 g
• c = 4.184 J/g·°C (water)
• ΔT = 80 − 20 = 60 °C
• q = 200 × 4.184 × 60 ≈ 50 200 J ≈ 50.2 kJ ≈ 12.0 kcal

Because q is positive, the process is endothermic: the water absorbs energy from its surroundings.

Worked example — cool a copper block

A 500 g copper block at 100 °C cools to 25 °C. How much energy does it release?

• m = 500 g
• c = 0.385 J/g·°C (copper)
• ΔT = 25 − 100 = −75 °C
• q = 500 × 0.385 × (−75) ≈ −14 440 J ≈ −14.4 kJ

The negative sign tells you energy left the copper — exothermic.

Energy units, in one table

All energies in this tool are computed internally in joules, then displayed in whatever unit you choose. The conversions:

About the data: Specific heat values follow the IUPAC 2021 and NIST reference data at standard conditions (room temperature, atmospheric pressure). Real specific heats vary mildly with temperature and pressure, so use these as a study-aid baseline rather than a substitute for tabulated lab values for your exact conditions.