Energy Converter
Convert joules, kilojoules, calories, kilocalories, watt-hours, kWh and BTU.
What do you want to convert?
Show this value in every unit
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About the Energy Converter
Energy appears as kWh on electricity bills, kcal on food labels, BTU on air-conditioner specifications and joules in science. This converter switches between all of them instantly.
How to use the Energy Converter
- Enter a value.
- Choose the units to convert from and to.
- Read the result and the quick table.
How it works
Every unit is converted through joules (J):
- 1 kJ = 1,000 J
- 1 cal = 4.184 J; 1 kcal (food calorie) = 4,184 J
- 1 Wh = 3,600 J; 1 kWh = 3,600,000 J
- 1 BTU = 1,055.06 J
Examples
- 1 kWh (one electricity unit) = 3,600 kJ = 3,412 BTU.
- 100 kcal = 418.4 kJ.
Frequently asked questions
Is a food Calorie the same as a calorie?
No. The Calorie on food labels is a kilocalorie (kcal), which is 1,000 small calories or 4.184 kJ.
Can I convert to other units too?
Yes. Choose any unit in the From and To lists, or use the main Unit Converter for length, weight, temperature and more.