Specific Heat Calculator
Calculate the heat energy needed to change a substance's temperature with Q = m·c·ΔT. Solve for any variable, pick from 19 material presets, switch mass and energy units, and enter ΔT directly or from an initial and final temperature.
Specific Heat Calculator
Pick a variable to solve for, then enter the other three. Everything updates live.
Result
About the Specific Heat Calculator
Specific heat capacity (c) is the amount of energy needed to raise the temperature of one kilogram of a substance by one kelvin (or one degree Celsius). It is what makes water so good at storing heat: water's specific heat of 4186 J/(kg·K) is far higher than that of metals like copper (385) or iron (449), which is why a metal pan heats up in seconds while the water inside takes minutes. The heat needed for a temperature change with no change of state is given by Q = m·c·ΔT, where Q is the heat energy in joules, m is the mass, c is the specific heat and ΔT is the temperature change. This calculator solves the equation in every direction — give it any three of the four quantities and it finds the fourth — and includes 19 accurate material presets, mass in grams or kilograms, energy in joules, kilojoules or calories, and a temperature-range mode that works out ΔT from an initial and final temperature. It is the core relationship behind calorimetry, the experimental measurement of heat used in chemistry, cooking, heating and cooling, and engineering.
How to use this calculator
- 1 Choose what to solve for: heat energy Q, mass m, specific heat c or temperature change ΔT.
- 2 Enter the other three values. Pick a material preset to fill in c automatically, switch mass (g/kg) and energy (J/kJ/cal) units as needed, and toggle "Use T₁ → T₂" to compute ΔT from a starting and ending temperature.
- 3 Read the answer with the formula above it, the solved variable highlighted, and the heat shown in J, kJ and cal.
How Q = mcΔT works
When you add heat to a substance without melting, boiling or otherwise changing its state, all of the energy goes into raising its temperature. The amount is: Q = m·c·ΔT where Q is the heat (joules), m is the mass (kg), c is the specific heat capacity (J/(kg·K)) and ΔT is the temperature change. Because a change of 1 K is the same size as a change of 1 °C, ΔT in kelvin equals ΔT in degrees Celsius — only the change matters, not the starting temperature. Rearranging the formula lets you solve for any quantity: • Heat: Q = m·c·ΔT • Mass: m = Q / (c·ΔT) • Specific heat: c = Q / (m·ΔT) • Temperature change: ΔT = Q / (m·c) For example, heating 1 kg of water (c = 4186) by 10 K takes Q = 1 × 4186 × 10 = 41,860 J = 41.86 kJ. Heat that flows out as a substance cools is the same equation with a negative ΔT. This is exactly the principle used in calorimetry, where the heat gained by one body equals the heat lost by another.
Frequently asked questions
What is specific heat?
Specific heat (or specific heat capacity) is the amount of energy needed to raise the temperature of one kilogram of a substance by one kelvin — equivalently one degree Celsius. It is measured in J/(kg·K). A high specific heat means the substance resists temperature change and stores a lot of heat: water's value of 4186 J/(kg·K) is one of the highest of any common substance, while metals are much lower (copper is 385, lead just 128), which is why metals heat and cool quickly.
How much energy does it take to heat water?
Use Q = m·c·ΔT with c = 4186 J/(kg·K) for water. To heat 1 kg of water by 10 °C you need Q = 1 × 4186 × 10 = 41,860 J ≈ 41.86 kJ (about 10 kcal). Heating it from 20 °C to 100 °C (ΔT = 80 °C) takes 1 × 4186 × 80 = 334,880 J ≈ 335 kJ. Water's large specific heat is why boiling a kettle takes meaningful time and energy.
What does Q = mcΔT mean?
It states that the heat Q needed to change a substance's temperature equals its mass m times its specific heat c times the temperature change ΔT. More mass, a higher specific heat or a bigger temperature change all require more energy. The equation applies only when there is no phase change (no melting or boiling); during a phase change the temperature stays constant and a separate quantity, the latent heat, applies instead.
What is the specific heat of water?
The specific heat of liquid water is 4186 J/(kg·K), or equivalently 4.186 J/(g·°C) — almost exactly 1 calorie per gram per degree Celsius, which is how the calorie was originally defined. Ice has a lower specific heat (about 2090 J/(kg·K)) and water vapor (steam) is lower still (about 2010 J/(kg·K)), because the molecules store energy differently in each state.
Related tools
Keep exploring physics on UnitConv. Model radioactive decay with the half-life calculator, convert between joules, calories and other energy units with the energy converter, explore temperature scales in the temperature converter, and try the molar mass and other science calculators.