Convert Kilocalories to Joules
kcal to J · energy conversion
What are kilocalories and joules?
A kilocalorie (the food Calorie) is 1,000 small calories, the unit on US nutrition labels. The joule is the SI unit of energy, the work done by one newton acting over one meter. For reference: a food Calorie is one kilocalorie (4,184 J), and home electricity is billed in kilowatt-hours.
How to convert kilocalories to joules
1 kcal = 4,184 J. To convert, multiply the number of kilocalories by 4,184. For example, 5 kcal = 20,920 J, and 20 kcal = 83,680 J. To go the other way, multiply joules by 0.000239006 (since 1 J = 0.000239006 kcal).
Kilocalories to Joules conversion table
| Kilocalories (kcal) | Joules (J) |
|---|---|
| 1 | 4,184 |
| 10 | 41,840 |
| 100 | 418,400 |
| 500 | 2,092,000 |
| 1,000 | 4,184,000 |
| 2,000 | 8,368,000 |
| 5,000 | 20,920,000 |
FAQ
What is 1 kcal in J?
1 kcal = 4,184 J. To convert any amount, multiply the number of kilocalories by 4,184.
How do I convert joules back to kilocalories?
Go the other way: 1 J = 0.000239006 kcal, so multiply joules by 0.000239006 to get kilocalories.
Is a kilocalorie bigger than a joule?
Yes — 1 kcal is the larger unit, equal to 4,184 J.
Are these energy conversions exact?
They use the standard internationally-defined conversion factors. Results are rounded to six significant figures for readability, which is accurate enough for everyday and most technical use.