Convert joules to calories instantly. Enter a value below, or use the formula and reference table further down the page.
In practice
Joules to calories divides by 4.184, since one thermochemical calorie is 4.184 joules. Food energy is more often quoted in kilojoules and kilocalories: 1,000 J is 239 cal, or 0.239 kcal, and a 2,000 kcal daily diet is about 8,368 kJ. When reading labels, check whether the number means calories (cal) or kilocalories (kcal, Calories) — the second is a thousand times larger and is the one nutrition information means. This conversion is for understanding figures, not for dietary advice.
How to convert joules to calories
Multiply the value by 0.2390057361.
cal = J × 0.2390057361Example: 10 J = 2.3901 cal.
Joules to Calories conversion table
| Joules (J) | Calories (cal) |
|---|---|
| 1 J | 0.239 cal |
| 2 J | 0.478 cal |
| 3 J | 0.717 cal |
| 4 J | 0.956 cal |
| 5 J | 1.195 cal |
| 10 J | 2.3901 cal |
| 15 J | 3.5851 cal |
| 20 J | 4.7801 cal |
| 25 J | 5.9751 cal |
| 50 J | 11.9503 cal |
| 100 J | 23.9006 cal |
Frequently asked questions
How many calories is 1 joule?
1 joule equals 0.239 calories.
What is the formula to convert J to cal?
To convert J to cal, multiply the value by 0.2390057361. The full formula is: cal = J × 0.2390057361.
How do I convert calories back to joules?
Use the same calculator above and type your value into the calories field instead — it converts in both directions. Or use the reverse formula: J = cal ÷ 0.2390057361.
Is the J to cal conversion exact?
The conversion factor used here (0.2390057361) is the standard internationally defined value. Results on this page are rounded to four decimal places for readability.