Energy converter
Convert between joules, kWh, calories, BTU and more.
Energy converter
Convert energy between joules (J), kilojoules (kJ), calories (cal), kilocalories (kcal), watt-hours (Wh), kilowatt-hours (kWh) and BTU. Handy for electricity bills, nutrition and physics. It all runs in your browser.
Useful equivalents
1 kWh = 3.6 MJ = 3,600,000 J ≈ 860 kcal. 1 cal = 4.184 J. 1 kcal (the food "calorie") = 4,184 J. 1 BTU ≈ 1,055 J.
What it’s for
- Electricity bills: usage is measured in kWh.
- Nutrition: food "calories" are kcal.
- Physics and engineering: joules and BTU.
Frequently asked questions
How many joules in 1 kWh? 3,600,000 J (3.6 MJ).
Calorie vs kilocalorie? The food "Calorie" (capital C) is usually 1 kcal = 1,000 cal.