Water Heating Calculator

Compute energy to heat a given volume of water.

How to Use This Calculator

Enter water volume in liters and initial/final temperatures in °C. The tool assumes 1 kg/L density and c = 4186 J/kg·K.

Formula

Q = m c ΔT

m ≈ volume (L) in kg, c ≈ 4186 J/kg·K

About Water Heating

This estimates ideal energy ignoring losses. Real systems need more energy due to tank and piping losses.

Frequently Asked Questions

How long will it take?

Divide energy (kWh) by heater power (kW) to estimate time in hours.

Does altitude matter?

Boiling point changes with altitude; specific heat is nearly constant near room conditions.