Specific Heat
Calculate heat, mass, specific heat, or ΔT with Q = mcΔT for calorimetry and heating problems. Free online calculator with formulas and step-by-step solutions.
Key formula
Q = mcΔT
How do you calculate heat with specific heat?
Use Q = m c ΔT. Multiply mass by specific heat by the temperature change. Rearrange to m = Q/(cΔT), c = Q/(mΔT), or ΔT = Q/(m c) when one quantity is missing.
About this tool
Specific heat capacity c tells how much heat energy it takes to raise one kilogram of a material by one degree. This page keeps Q = mcΔT visible so you can solve for heat, mass, c, or temperature change without losing the unit checks that usually cost marks.
How to use this calculator
- Choose the variable you want to solve for and confirm which values are already known.
- Enter inputs in consistent units before calculating so the formula is applied correctly.
- Check whether the result is physically reasonable by comparing it with the size of the inputs.
- Use the step-by-step breakdown to see how the equation was rearranged and evaluated.
Worked examples
Example 1: heat 2.0 kg of water by 5.0 °C
m = 2.0 kg, c = 4186 J/(kg·°C), ΔT = 5.0 °C. Q = (2.0)(4186)(5.0) = 41 860 J ≈ 41.86 kJ.
Example 2: find c from a lab
Q = 2500 J warms m = 0.50 kg by ΔT = 10 °C. c = Q/(mΔT) = 2500 / (0.50 × 10) = 500 J/(kg·°C).
Example 3: find ΔT for aluminum
Q = 9000 J, m = 1.0 kg, c ≈ 900 J/(kg·°C). ΔT = Q/(m c) = 9000 / (1.0 × 900) = 10 °C.
Frequently asked questions
What is the specific heat formula?
Q = m c ΔT, where Q is heat energy, m is mass, c is specific heat capacity, and ΔT is the temperature change. Solve for any one unknown when the other three are known.
Is ΔT in Celsius or Kelvin?
A temperature change of 1 °C equals a change of 1 K, so ΔT is numerically the same in either scale. Do not convert like an absolute temperature (no +273 for ΔT alone).
What is a typical c for water?
Liquid water is often taken as about 4186 J/(kg·°C) or 4.186 J/(g·°C). Use the value printed on the paper when it differs.
Can Q be negative?
If the object cools, ΔT is negative and Q is negative (heat leaves the object). Many homework answers report |Q| as heat released; follow the sign convention on the paper.
How is specific heat different from heat capacity?
Specific heat c is per unit mass (J/(kg·°C)). Heat capacity C = m c is for the whole sample (J/°C). This calculator uses the per-kilogram form Q = mcΔT.