Joules to Calories Converter
1 joule ≈ 0.239005736 calories
This is the small calorie. The "Calorie" on food labels is a kilocalorie, which is 1,000 of these.
1 joule equals 0.239006 calories
How to convert joules to calories
Calories here are thermochemical (4.184 J), while BTU uses the International Table definition. A kilowatt-hour is energy (3.6 MJ), not power; a food Calorie is a kilocalorie.
cal = J ÷ 4.184One calorie corresponds to 4.184 joules, so divide by that figure. Displayed constants may be rounded; the converter uses the stored factor before rounding the result.
2.39006 cal ≈ 10 ÷ 4.184This is the small calorie. The "Calorie" on food labels is a kilocalorie, which is 1,000 of these.
Joules to calories conversion table
Common values in joules, converted to calories.
| Joules (J) | Calories (cal) |
|---|---|
| 1 | 0.23900574 |
| 2 | 0.47801147 |
| 3 | 0.71701721 |
| 4 | 0.95602294 |
| 5 | 1.1950287 |
| 10 | 2.3900574 |
| 20 | 4.7801147 |
| 25 | 5.9751434 |
| 50 | 11.950287 |
| 100 | 23.900574 |
| 250 | 59.751434 |
| 500 | 119.50287 |
| 1,000 | 239.00574 |
About these units
jouleJ
The SI derived unit of energy: one newton acting through one metre.
caloriecal
The thermochemical calorie: exactly 4.184 joules.
Reference: NIST Special Publication 811.
Sources and precision
Table results are rounded to 8 significant digits; formula constants may be rounded to 10. Worked example answers use 6 significant digits. The converter starts at 6 significant digits and lets you change display precision. Calculations use the stored factors without intermediate rounding. Exact unit definitions do not make an input measurement more precise; conventional and measured factors follow the assumptions stated here.