How to use this calculator
Enter the mass, pick a material (or type its specific heat), and give the starting and final temperatures. Add a heating time to get the average power.
Formulas
Sensible heatQ = mcΔT
Average powerP = Qt
Worked example
Heating 2 kg of water from 20 to 80 °C in 10 minutes (the default)
- ΔT = 80 − 20 = 60 K.
- Q = 2 × 4,186 × 60 = 502 kJ.
- P = 502,320 J / 600 s = 837 W before heat losses.
Frequently asked questions
Why does water take so much energy to heat?
Its specific heat (about 4.19 kJ/kg·K) is unusually high, more than four times that of air or aluminum.
What about melting or boiling?
Add latent heat: 334 kJ/kg to melt ice and about 2,257 kJ/kg to boil water at 1 atm.