How to convert calories (small) to joules
One calorie (small) equals 4.184 joules, so multiply the number of calories (small) by 4.184:
J = cal × 4.184
cal = J ÷ 4.184 (1 J = 0.239006 cal)
Example: 100 cal → 100 × 4.184 = 418.4 J.
Going the other way, divide by 4.184, or multiply by 0.239006; the joules to calories (small) converter does it for you.
Everyday values
| Calories (small) | Joules | For example |
|---|---|---|
| 1 cal | 4.184 J | one calorie |
| 100 cal | 418.4 J | 100 cal |
| 1,000 cal | 4,184 J | one kcal (food Calorie) |
When you need this conversion
Multiply calories by 4.184 to get joules. One calorie is roughly the energy needed to warm 1 gram of water by 1 °C.
Calorie (small) to joule conversion table
| cal | J | cal | J |
|---|---|---|---|
| 10 cal | 41.84 J | 110 cal | 460.24 J |
| 20 cal | 83.68 J | 120 cal | 502.08 J |
| 30 cal | 125.52 J | 130 cal | 543.92 J |
| 40 cal | 167.36 J | 140 cal | 585.76 J |
| 50 cal | 209.2 J | 150 cal | 627.6 J |
| 60 cal | 251.04 J | 160 cal | 669.44 J |
| 70 cal | 292.88 J | 170 cal | 711.28 J |
| 80 cal | 334.72 J | 180 cal | 753.12 J |
| 90 cal | 376.56 J | 190 cal | 794.96 J |
| 100 cal | 418.4 J | 200 cal | 836.8 J |
About the units
- Calorie (small) (cal): the thermochemical calorie, exactly 4.184 J; 1,000 of them make one food Calorie (kcal).
- Joule (J): the SI unit of energy.
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 joules are in one calorie (small)?
One calorie (small) is 4.184 joules. One joule is 0.239006 calories (small).
How do I convert calories (small) to joules?
Multiply the value in calories (small) by 4.184. To go back, divide by 4.184.
What is 100 cal in joules?
100 cal = 418.4 J.
What is 1,000 cal in joules?
1,000 cal = 4,184 J.
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.