Joules to Calories (J to cal)
1 J = 0.239006 cal
To convert joules to calories: calories = joules ÷ 4.184
| joules | calories |
|---|---|
| 1 J | 0.239 cal |
| 4.184 J | 1 cal |
| 10 J | 2.39 cal |
| 100 J | 23.9 cal |
| 500 J | 119.5 cal |
| 1,000 J | 239 cal |
| 4,184 J | 1,000 cal |
| 10,000 J | 2,390 cal |
Food energy: kJ ÷ 4.184 = kcal (food Calories). 2,000 kJ = 478 kcal; 8,400 kJ (a typical daily intake) = 2,008 kcal.
One thermochemical calorie is defined as exactly 4.184 joules (NIST SP 811), so divide joules by 4.184 to get calories. 100 J is 23.9 cal. Chemistry and physics problems use this small calorie.
Formula
calories = joules ÷ 4.184
Example: 50 joules = 11.9503 calories.
Joules to Calories chart
| joules | calories |
|---|---|
| 1 | 0.239006 |
| 4.184 | 1 |
| 10 | 2.39006 |
| 50 | 11.9503 |
| 100 | 23.9006 |
| 200 | 47.8011 |
| 418.4 | 100 |
| 500 | 119.503 |
| 1,000 | 239.006 |
| 2,000 | 478.011 |
| 4,184 | 1,000 |
| 5,000 | 1,195.03 |
| 10,000 | 2,390.06 |
| 100,000 | 23,900.6 |
Good to know
Food labels are different: the 'Calorie' on a US label is a kilocalorie (1 kcal = 1,000 cal = 4,184 J). A label that says 1,000 kJ is 239 kcal, the food Calories you count. Divide kJ by 4.184 for kcal.
The International Table calorie (4.1868 J) is used for steam and some engineering tables; it differs by 0.07%, so 1,000 J is 238.85 cal instead of 239.01 cal.
Heat and work: lifting 1 kg by 1 m takes 9.81 J, or 2.34 cal. Warming 1 g of water by 1 °C takes about 1 cal, which is where the unit came from. For kWh, BTU and every other unit, use the energy converter.
Frequently asked questions
How many calories is 1 joule?
1 J is 0.239006 calories (1 ÷ 4.184).
How do you convert joules to calories?
Divide by 4.184. 500 J ÷ 4.184 = 119.5 cal.
How many kcal is 1,000 kJ?
1,000 kJ is 239 kcal (divide kJ by 4.184), the food Calories on a nutrition label.
Is a food Calorie the same as a calorie?
No. A food Calorie (capital C) is a kilocalorie, 1,000 small calories or 4,184 J.