Joule to Calorie Converter
Converts joule to calorie (J to cal) and back. The conversion factor is shown below every result.
How to Convert Joule to Calorie
What Is a Joule?
The joule (J) is the SI unit of energy, equal to one newton-meter.
What Is a Calorie?
The thermochemical calorie (cal) is defined as exactly 4.184 joules. This is the small calorie used in chemistry and physics, not the food-label Calorie (kcal), which is 1,000 times larger.
Common Joule to Calorie Reference Points
Real-world reference values for quick sanity checks.
| Item | Joule (J) | Calorie (approx.) |
|---|---|---|
| Energy to lift a small apple 1 meter (approx.) | 1 J | 0.239 cal |
| A typical AA battery's stored energy (approx.) | 9000 J | 2,151.05 cal |
| Reference values are illustrative approximations for common items, not measured specifications. | ||
Joule to Calorie Conversion Table
| Joule (J) | Calorie (cal) |
|---|---|
| 1 J | 0.239006 cal |
| 10 J | 2.390057 cal |
| 100 J | 23.900574 cal |
| 1000 J | 239.005736 cal |
| 4184 J | 1000 cal |
| 9000 J | 2151.051625 cal |
| 10000 J | 2390.057361 cal |
| Source: NIST SP 811, footnotes (1 cal = 4.184 J exactly, thermochemical calorie) | |
Frequently Asked Questions
How do I convert joules to calories?
Multiply the joule value by 0.2390057361. For example, 500 J × 0.2390057361 = 119.503 cal.
Is this the same calorie as on a food nutrition label?
No. This page converts to the small (thermochemical) calorie, used in physics and chemistry. The food-label Calorie (capital C, also called a kilocalorie or kcal) is 1,000 times larger; 1 food Calorie = 4,184 J, not 4.184 J.
How many joules are in a food Calorie?
4,184 joules, since 1 food Calorie = 1 kcal = 1,000 small calories, and 1 small calorie = 4.184 J.
Related Energy Converters
A good measuring tool marked in both J and cal removes the guesswork at the point of use.