How to convert kilojoules to kilocalories
One kilojoule equals 0.239006 kilocalories, so multiply the number of kilojoules by 0.239006:
kcal = kJ × 0.239006
kJ = kcal ÷ 0.239006 (1 kcal = 4.184 kJ)
Example: 100 kJ → 100 × 0.239006 = 23.9006 kcal.
Going the other way, divide by 0.239006, or multiply by 4.184; the kilocalories to kilojoules converter does it for you.
Everyday values
| Kilojoules | Kilocalories | For example |
|---|---|---|
| 100 kJ | 23.9006 kcal | 100 kJ |
| 500 kJ | 119.503 kcal | a light snack |
| 1,000 kJ | 239.006 kcal | a small meal |
| 8,400 kJ | 2,007.65 kcal | the EU daily reference intake |
| 8,700 kJ | 2,079.35 kcal | the Australian average adult daily intake used on labels |
When you need this conversion
Australian and New Zealand food labels lead with kilojoules. Dividing by 4.184 gives kilocalories; dividing by 4 is a quick estimate. The average adult daily energy intake used on Australian labels is 8,700 kJ, about 2,080 kcal.
Kilojoule to kilocalorie conversion table
| kJ | kcal | kJ | kcal |
|---|---|---|---|
| 100 kJ | 23.9006 kcal | 1,100 kJ | 262.906 kcal |
| 200 kJ | 47.8011 kcal | 1,200 kJ | 286.807 kcal |
| 300 kJ | 71.7017 kcal | 1,300 kJ | 310.707 kcal |
| 400 kJ | 95.6023 kcal | 1,400 kJ | 334.608 kcal |
| 500 kJ | 119.503 kcal | 1,500 kJ | 358.509 kcal |
| 600 kJ | 143.403 kcal | 1,600 kJ | 382.409 kcal |
| 700 kJ | 167.304 kcal | 1,700 kJ | 406.31 kcal |
| 800 kJ | 191.205 kcal | 1,800 kJ | 430.21 kcal |
| 900 kJ | 215.105 kcal | 1,900 kJ | 454.111 kcal |
| 1,000 kJ | 239.006 kcal | 2,000 kJ | 478.011 kcal |
About the units
- Kilojoule (kJ): 1,000 joules.
- Kilocalorie (kcal): the thermochemical kilocalorie, exactly 4,184 joules (the 'Calorie' on food labels).
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 kilocalories are in one kilojoule?
One kilojoule is 0.239006 kilocalories. One kilocalorie is 4.184 kilojoules.
How do I convert kilojoules to kilocalories?
Multiply the value in kilojoules by 0.239006. To go back, divide by 0.239006.
What is 100 kJ in kilocalories?
100 kJ = 23.9006 kcal.
What is 500 kJ in kilocalories?
500 kJ = 119.503 kcal.
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.