How to convert joules to calories
One joule equals 0.239006 calories. To convert, multiply the number of joules by 0.239006 (or divide by 4.184):
Mental-math shortcut: Divide joules by 4.184 to get small calories; divide again by 1,000 for food Calories (kcal).
Example
Convert 1,000 joules to calories: 1,000 J × 0.239006 = 239.01 cal.
Joules to Calories (small) conversion chart
| Joules (J) | Calories (small) (cal) |
|---|---|
| 1 | 0.239006 |
| 4.184 | 1 |
| 10 | 2.3901 |
| 50 | 11.9503 |
| 100 | 23.9006 |
| 500 | 119.5 |
| 1,000 | 239.01 |
| 4,184 | 1,000 |
| 5,000 | 1,195.03 |
| 10,000 | 2,390.06 |
| 100,000 | 23,900.57 |
What is a joule?
The joule (J) is the SI unit of energy: the work done by a force of one newton over one meter, or one watt for one second. It is a small unit — lifting an apple about one meter takes roughly 1 J — so food energy is usually given in kilojoules.
What is a calorie?
A small calorie (cal) is the energy needed to warm one gram of water by 1 °C, defined as exactly 4.184 joules. It is used in chemistry and physics. The "Calories" on food labels are actually kilocalories: 1 food Calorie = 1 kcal = 1,000 small calories.
Converting the other way? Use the Calories (small) to Joules converter.
Frequently asked questions
How many calories is one joule?
One joule is 0.239006 calories.
How do I convert joules to calories?
Multiply the value in joules by 0.239006. For example, 1,000 J × 0.239006 = 239.01 cal.
What is 4,184 J in calories?
4,184 J is 1,000 calories.
How do I convert calories to joules?
Multiply calories by 4.184 (or divide by 0.239006). You can also use our Calories (small) to Joules converter.
Conversions use the internationally agreed definitions of each unit (for example, 1 inch = 2.54 cm exactly) and are rounded for display. Volume converters use US customary units unless stated otherwise.
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