Energy Converter
Convert between joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, and BTU instantly in your browser.
How to use the Energy Converter
- Enter the value you want to convert.
- Choose the unit you are converting from.
- Choose the unit you are converting to.
- Click Run to see the converted value, for example 1 kcal = 4.184 kJ.
How the Energy Converter works
All energy units are converted through the joule, the SI unit of energy. Key factors: 1 calorie (thermochemical) = 4.184 J, so 1 kilocalorie (the "Calorie" on food labels) = 4,184 J; 1 watt-hour = 3,600 J and 1 kilowatt-hour = 3.6 million J; 1 BTU ≈ 1,055 J.
That makes it easy to compare, say, the energy in food with electricity use: a 500 kcal meal holds about 0.58 kWh, roughly the energy a 60 W bulb uses in ten hours.
Frequently asked questions
- Is this energy converter free?
- Yes. Convert energy at no cost, with no account required.
- Which units are supported?
- Joules, kilojoules, calories, kilocalories, watt-hours, kilowatt-hours, and BTU.