Toolzy

Energy Converter

Convert energy between joules, calories, kilocalories, kWh, eV, and BTU.

  • Joule (J)1,000
  • Calorie (cal)239.005736
  • Kilocalorie (kcal)0.239006
  • Kilowatt-hour (kWh)0.000278
  • Electronvolt (eV)6,241,509,074,460,763,000,000
  • British thermal unit (BTU)0.947817

Enter a value and its unit to instantly convert it into every other energy unit, from joules to electronvolts.

How to use

  1. Enter the energy value you want to convert.
  2. Select the unit that value is in.
  3. Read the equivalent in every other unit below.

Frequently asked questions

How many joules are in a calorie?
One calorie equals 4.184 joules, and one kilocalorie (food Calorie) equals 4184 joules.
What is an electronvolt?
An electronvolt (eV) is a tiny energy unit used in physics, equal to about 1.602 × 10⁻¹⁹ joules.

Related tools