Calories to Kilojoules
Convert calories (kcal) to kilojoules (kJ) instantly — with formula and reference table.
kcal
kJ
Quick answer: 1 kcal = 4.184 kJ. To convert calories to kilojoules, multiply by kcal × 4.184.
Converting calories to kilojoules
This converter changes a value in calories (kcal) into kilojoules (kJ). One calorie equals 4.184 kJ. One kilocalorie (food Calorie) equals exactly 4.184 kilojoules. The conversion runs entirely in your browser — enter a value and the result updates instantly, in either direction.
Formula
kJ = kcal × 4.184
Example
Convert 10 kcal to kJ: 10 × 4.184 = 41.84 kJ.
Calories to Kilojoules conversion table
| Calories (kcal) | Kilojoules (kJ) |
|---|---|
| 1 kcal | 4.184 kJ |
| 2 kcal | 8.368 kJ |
| 3 kcal | 12.552 kJ |
| 5 kcal | 20.92 kJ |
| 10 kcal | 41.84 kJ |
| 20 kcal | 83.68 kJ |
| 25 kcal | 104.6 kJ |
| 50 kcal | 209.2 kJ |
| 100 kcal | 418.4 kJ |
How to use this converter
- Enter a value in the calories (kcal) field.
- Read the converted value in kilojoules (kJ) below.
- Type into the kJ field instead to convert in reverse, or use the swap button.
Frequently asked questions
How many kilojoules are in a calorie?
1 kilocalorie equals 4.184 kilojoules.
How do I convert 500 kcal to kJ?
500 times 4.184 = 2092 kJ.
Why do labels show both kJ and kcal?
The EU and Australia require kilojoules; the US uses Calories (kcal). Many labels list both.