Latent Heat Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026Energy that changes state, not temperature
Latent heat is absorbed or released during a phase change at constant temperature - this is why ice stays at exactly 0C while melting and water stays at exactly 100C while boiling, even as heat continues flowing into the substance the entire time.
Worked example
For 1kg of water vaporizing (latent heat of vaporization 2260 kJ/kg):
Q = 1 x 2260 = 2260.0 kJ
Frequently asked questions
Why doesn't temperature rise during a phase change? All the added energy goes into breaking intermolecular bonds (overcoming attractive forces holding molecules together in the solid or liquid state) rather than increasing molecular kinetic energy, which is what a thermometer actually measures.
Why is water's latent heat so significant practically? Water's latent heat of vaporization (2260 kJ/kg) is unusually high, which is exactly why sweating is such an effective cooling mechanism and why steam burns are far more severe than boiling water burns at the same temperature - steam releases this large latent heat directly into skin upon condensing.