The heat transfer calculator uses Q = mcΔT to calculate the heat energy absorbed or released by a substance. Enter mass, specific heat capacity, and temperature change. Results shown in Joules, calories, and BTU. Supports °C and °F temperature input.
Heat Transfer Calculator (Q = mcΔT)
How to Use the Heat Transfer Calculator
Q = mcΔT calculates heat absorbed or released by a substance. Use it for calorimetry problems, heat exchanger design, and energy calculations.
Specific Heat Presets
Click a material preset to load its specific heat. Water (4,186 J/kg·°C) has the highest specific heat of common substances, which is why it's used as a coolant and makes coastal climates mild.
Temperature Units
Select °C or °F for temperature input. Note that ΔT is the same in Celsius and Kelvin — a 10°C rise = 10 K rise = 18°F rise. The calculator converts °F differences automatically.
Example
Heating 2 kg of water from 20°C to 100°C: Q = 2 × 4186 × 80 = 669,760 J ≈ 670 kJ ≈ 160 kcal ≈ 635 BTU. This is the energy needed to bring 2 liters of water to a boil starting from room temperature.
FAQ
What is the heat transfer formula?
Q = mcΔT, where Q is heat energy (joules), m is mass (kg), c is specific heat capacity (J/kg·°C), and ΔT is temperature change (°C or K). Water's specific heat is 4,186 J/kg·°C — it takes 4,186 J to raise 1 kg of water by 1°C.
What is specific heat capacity?
Specific heat capacity is the energy required to raise 1 kg of a substance by 1°C. Water: 4,186 J/kg·°C. Aluminum: 897 J/kg·°C. Iron: 449 J/kg·°C. Air: 1,005 J/kg·°C. Substances with high specific heat capacity absorb more energy before heating up — this is why coastal cities have milder climates than inland ones.
Is this calculator free?
Yes, completely free with no signup required. All calculations run in your browser.
Is my data private?
Yes. All calculations run locally. Nothing is transmitted.
How do I convert between Joules, calories, and BTU?
1 calorie = 4.184 J. 1 food Calorie (kcal) = 4,184 J. 1 BTU = 1,055.06 J. To heat 1 pound of water by 1°F requires exactly 1 BTU — this is the definition of the BTU. This tool shows results in all three units simultaneously.