All tools
Energy Converter
Convert energy between joules, calories, kilocalories, watt-hours, and kilowatt-hours. Runs in your browser.
1 Kilocalorie =
4.184
Kilojoule
Your inputs never leave your device.
Convert energy between joules, kilojoules, calories, kilocalories, watt-hours, and kilowatt-hours. Useful for nutrition, physics, and electricity.
How to use
- Enter the energy value.
- Choose the from and to units.
- The result updates instantly.
Frequently asked questions
How many joules in a calorie?
One calorie is about 4.184 joules, and one kilocalorie (the 'calorie' on food labels) is 4184 joules. The tool converts between them.
Is a food Calorie the same as a calorie?
The 'Calorie' on nutrition labels is actually a kilocalorie (1000 calories). Use kcal for food energy in this tool.
How do I convert kWh to joules?
One kilowatt-hour is 3,600,000 joules. Select kWh and joule to convert.