Calories to Kilojoules Converter (kcal to kJ)
Convert calories to kilojoules instantly with our free kcal to kJ calculator. Enter a value to see the result.
How to convert calories to kilojoules
To change kcal into kJ, use this formula:
Quick mental estimate: multiply by about 4.2.
Example: to convert 25 kcal to kJ, calculate 104.6 kJ. To go the other way, use kcal = kJ ÷ 4.184.
Popular calories to kilojoules conversions
- 1 kcal to kJ = 4.184 kJ
- 2 kcal to kJ = 8.368 kJ
- 3 kcal to kJ = 12.552 kJ
- 5 kcal to kJ = 20.92 kJ
- 10 kcal to kJ = 41.84 kJ
- 15 kcal to kJ = 62.76 kJ
- 20 kcal to kJ = 83.68 kJ
- 25 kcal to kJ = 104.6 kJ
- 30 kcal to kJ = 125.52 kJ
- 40 kcal to kJ = 167.36 kJ
- 50 kcal to kJ = 209.2 kJ
- 60 kcal to kJ = 251.04 kJ
- 70 kcal to kJ = 292.88 kJ
- 80 kcal to kJ = 334.72 kJ
- 90 kcal to kJ = 376.56 kJ
- 100 kcal to kJ = 418.4 kJ
Calories to Kilojoules conversion chart
| Calories (kcal) | Kilojoules (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 |
| 25 kcal | 104.6 kJ |
| 50 kcal | 209.2 kJ |
| 75 kcal | 313.8 kJ |
| 100 kcal | 418.4 kJ |
| 250 kcal | 1,046 kJ |
| 500 kcal | 2,092 kJ |
| 1,000 kcal | 4,184 kJ |
When do you need kcal to kJ conversion?
This conversion is commonly used for nutrition, electricity bills and physics. Different countries and industries use different units, so converting calories to kilojoules helps you compare measurements accurately.
Frequently asked questions
How many kilojoules are in 1 calories?
1 kcal equals 4.184 kJ.
How do I convert calories to kilojoules?
Use the formula kJ = kcal × 4.184. For example, 25 kcal = 104.6 kJ.
What is 10 kcal in kJ?
10 kcal = 41.84 kJ.
What is 100 kcal in kJ?
100 kcal = 418.4 kJ.
How do I convert kJ back to kcal?
Use kcal = kJ ÷ 4.184. You can also use our Kilojoules to Calories converter.
Is this kcal to kJ converter accurate?
Yes. It uses standard international conversion factors and shows up to 6 significant digits.