How to convert joules to calories (small)
One joule equals 0.239006 calories (small), so multiply the number of joules by 0.239006:
cal = J × 0.239006
J = cal ÷ 0.239006 (1 cal = 4.184 J)
Example: 4.184 J → 4.184 × 0.239006 = 1 cal.
Going the other way, divide by 0.239006, or multiply by 4.184; the calories (small) to joules converter does it for you.
Everyday values
| Joules | Calories (small) | For example |
|---|---|---|
| 4.184 J | 1 cal | one calorie |
| 1,000 J | 239.006 cal | one kilojoule |
| 4,184 J | 1,000 cal | one food Calorie (kcal) |
When you need this conversion
In physics and chemistry, the small calorie (cal) is 4.184 J. Food labels use the kilocalorie, written "Calorie" or "kcal", which is 1,000 times larger; for food energy use the kJ to kcal converter.
Joule to calorie (small) conversion table
| J | cal | J | cal |
|---|---|---|---|
| 100 J | 23.9006 cal | 1,100 J | 262.906 cal |
| 200 J | 47.8011 cal | 1,200 J | 286.807 cal |
| 300 J | 71.7017 cal | 1,300 J | 310.707 cal |
| 400 J | 95.6023 cal | 1,400 J | 334.608 cal |
| 500 J | 119.503 cal | 1,500 J | 358.509 cal |
| 600 J | 143.403 cal | 1,600 J | 382.409 cal |
| 700 J | 167.304 cal | 1,700 J | 406.31 cal |
| 800 J | 191.205 cal | 1,800 J | 430.21 cal |
| 900 J | 215.105 cal | 1,900 J | 454.111 cal |
| 1,000 J | 239.006 cal | 2,000 J | 478.011 cal |
About the units
- Joule (J): the SI unit of energy.
- Calorie (small) (cal): the thermochemical calorie, exactly 4.184 J; 1,000 of them make one food Calorie (kcal).
Both are units of energy. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many calories (small) are in one joule?
One joule is 0.239006 calories (small). One calorie (small) is 4.184 joules.
How do I convert joules to calories (small)?
Multiply the value in joules by 0.239006. To go back, divide by 0.239006.
What is 4.184 J in calories (small)?
4.184 J = 1 cal.
What is 1,000 J in calories (small)?
1,000 J = 239.006 cal.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.