Energy Converter
Convert joules, kilojoules, calories, kilocalories, kWh and BTU instantly. Free, no sign-up.
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How to use Energy Converter
- Pick the unit your energy value is in.
- Enter the value and click Convert.
- See the energy in joules, calories, kWh, BTU and more.
Note: this tool runs in your browser. Nothing is uploaded.
Frequently Asked Questions
How many joules is 1 kWh?
1 kilowatt-hour equals 3,600,000 joules (3.6 MJ). Enter 1 kWh in the converter to see every equivalent unit.
How many calories are in a kilojoule?
1 kilojoule equals about 239 calories (1 kcal = 4.184 kJ). Food 'calories' on labels are actually kilocalories (kcal).
What is a BTU?
A British Thermal Unit is the energy needed to raise one pound of water by one degree Fahrenheit — about 1,055 joules. It is common in heating and air-conditioning ratings.
Is this energy converter free?
Yes, it is 100% free with no sign-up, and it runs entirely in your browser.