Calories to kJ Converter
Convert kilocalories (food Calories) (kcal) to kilojoules (kJ) instantly. Type a value — the result updates as you type, and the swap button converts the other way.
Calories to kJ formula
kJ = kcal × 4.184
1 kilocalorie (food Calorie) = 4.18 kilojoules · 1 kilojoule = 0.239 kilocalories (food Calories)
To convert kilocalories (food Calories) to kilojoules, multiply the value by 4.184. For example, 2000 kcal:
kJ = 2000 × 4.184kJ = 8368
So 2000 kcal = 8368 kJ.
Mental math shortcut
This conversion is exact, so there is no need to estimate: just multiply by 4.184.
Calories to kJ conversion table
kJ back to Calories
The same values converted the other way, rounded for everyday use:
| Kilojoules | Kilocalories (food Calories) |
|---|---|
| 209.2 kJ | 50 kcal |
| 418.4 kJ | 100 kcal |
| 836.8 kJ | 200 kcal |
| 1046 kJ | 250 kcal |
| 2092 kJ | 500 kcal |
| 4184 kJ | 1000 kcal |
| 6276 kJ | 1500 kcal |
| 8368 kJ | 2000 kcal |
About the units
Kilocalories (food Calories) (kcal)
A kilocalorie is 1,000 small calories, written “Calorie” on food labels. 1 kcal = 4.184 kJ.
Kilojoules (kJ)
A kilojoule is 1,000 joules. Food labels in Australia, the EU and elsewhere show energy in kJ.
Frequently asked questions
How many kilojoules are in a kilocalorie (food Calorie)?
One kilocalorie (food Calorie) equals 4.18 kilojoules.
What is 2000 Calories in kJ?
2000 kcal = 8368 kJ.
How do I convert kJ back to Calories?
Divide the kilojoules by 4.184. Or use the kJ to Calories converter.