Energy Converter
Energy converter: joules, kilojoules, calories, kilocalories, kWh, electronvolts, BTU and foot-pounds.
How to use this calculator
- Type the value you want to convert.
- Choose the unit you are converting from and the one you want.
- Read the result, or the full table of equivalent units below.
Convert energy across physics, chemistry, nutrition and electricity: joules, thermochemical calories, food kilocalories, kilowatt-hours, electronvolts and BTU.
The thermochemical calorie is exactly 4.184 J; the food “Calorie” on nutrition labels is a kilocalorie. One kilowatt-hour is exactly 3.6 MJ.
Conversion formula
1 kcal = 4.184 kJ · 1 kJ = 0.239006 kcal
Common conversions: kilocalorie → kilojoule
| kcal | kJ |
|---|---|
| 1 kcal | 4.184 kJ |
| 2 kcal | 8.368 kJ |
| 5 kcal | 20.92 kJ |
| 10 kcal | 41.84 kJ |
| 20 kcal | 83.68 kJ |
| 50 kcal | 209.2 kJ |
| 100 kcal | 418.4 kJ |
| 1 000 kcal | 4 184 kJ |
Frequently asked questions
How many joules are in a calorie?
4.184 J (thermochemical calorie).
How many kJ is 100 kcal?
418.4 kJ.