Calories to Kilojoules Converter
Convert calories to kilojoules instantly. 1 cal = 0.004184 kJ. Free two-way converter with the formula and a quick reference table.
How to convert calories to kilojoules
kilojoules = calories × 0.004184
One calorie equals 0.004184 kilojoules, so to convert calories to kilojoules you multiply by 0.004184. Going the other way, one kilojoule is 239.01 calories. Both units measure energy, so the conversion is an exact ratio that never changes.
10 calories = 0.04184 kilojoules. Multiply your calorie figure by the factor above (or just type it into the box) to convert any amount.
Need the other direction? kilojoules to calories
calories to kilojoules table
| calories (cal) | kilojoules (kJ) |
|---|---|
| 1 | 0.004184 |
| 2 | 0.008368 |
| 3 | 0.012552 |
| 5 | 0.02092 |
| 10 | 0.04184 |
| 20 | 0.08368 |
| 25 | 0.1046 |
| 50 | 0.2092 |
| 100 | 0.4184 |
| 250 | 1.046 |
| 500 | 2.092 |
| 1,000 | 4.184 |
Frequently asked questions
How many kilojoules are in a calorie?
One calorie equals 0.004184 kilojoules. So to convert, multiply the number of calories by 0.004184.
How do I convert calories to kilojoules?
Multiply by 0.004184, or simply enter the value in the converter above — it does the math instantly and works both ways.
Is this conversion exact?
Yes — both units measure the same quantity, so the ratio is fixed and this uses the standard internationally-agreed factor.