Energy to Heat 1 kg of Water from 20°C to 100°C
Heating 1 kg of water from 20°C to 100°C (ΔT = 80°C) requires 334 880 J, or about 334.9 kJ.
How to use this tool
- Enter mass, specific heat capacity and temperature change δt in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your heat energy q and the full breakdown beneath it.
Bringing a full kilogram of water to boiling point from room temperature requires roughly 335 kJ of heat energy.
Frequently asked questions
- What are common specific heat values?
- Water: 4186 J/kg·K (very high — why it's used as a coolant), iron: 450, aluminium: 900, copper: 385, ethanol: 2440 J/kg·K.
- Is ΔT in Celsius or Kelvin?
- Either, since a change of 1 °C equals a change of 1 K. Always use the magnitude of the change.