Energy converter
Kilojoules to Kilocalories
Converting Kilojoules to Kilocalories is a single multiplication when you know the factor. One kJ equals 0.23900574 kcal, so multiply the value in kJ by 0.23900574. The calculator below works in both directions and accepts decimals.
Formula 1 kJ = 0.23900574 kcal
Need the other direction? Kilocalories to Kilojoules.
How to convert Kilojoules to Kilocalories
A kilojoule is 1,000 joules and appears on nutrition labels in many countries. A kilocalorie is 4,184 joules and is the Calorie printed on food labels.
To convert Kilojoules to Kilocalories, multiply the value in kJ by 0.23900574. For example, 10 kJ × 0.23900574 = 2.390057 kcal. This works because the ratio between the two units is constant for every value in energy.
Worked examples
| kJ | kcal |
|---|---|
| 1 kJ | 0.23900574 kcal |
| 2.5 kJ | 0.59751434 kcal |
| 5 kJ | 1.195029 kcal |
| 10 kJ | 2.390057 kcal |
| 25 kJ | 5.975143 kcal |
| 50 kJ | 11.950287 kcal |
| 100 kJ | 23.900574 kcal |
Reverse conversion
| kcal | kJ |
|---|---|
| 1 kcal | 4.184 kJ |
| 5 kcal | 20.92 kJ |
| 10 kcal | 41.84 kJ |
| 25 kcal | 104.6 kJ |
| 50 kcal | 209.2 kJ |
| 100 kcal | 418.4 kJ |
When this conversion is useful
This is the calculation you need when you are comparing a nutrition label, an electricity bill or a heating system. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 kJ is 239.005736 kcal.
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
kJ to kcal conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Kilojoules (kJ) | Kilocalories (kcal) |
|---|---|
| 1 kJ | 0.23900574 kcal |
| 2 kJ | 0.47801147 kcal |
| 3 kJ | 0.71701721 kcal |
| 4 kJ | 0.95602294 kcal |
| 5 kJ | 1.195029 kcal |
| 6 kJ | 1.434034 kcal |
| 7 kJ | 1.67304 kcal |
| 8 kJ | 1.912046 kcal |
| 9 kJ | 2.151052 kcal |
| 10 kJ | 2.390057 kcal |
| 11 kJ | 2.629063 kcal |
| 12 kJ | 2.868069 kcal |
| 13 kJ | 3.107075 kcal |
| 14 kJ | 3.34608 kcal |
| 15 kJ | 3.585086 kcal |
| 16 kJ | 3.824092 kcal |
| 17 kJ | 4.063098 kcal |
| 18 kJ | 4.302103 kcal |
| 19 kJ | 4.541109 kcal |
| 20 kJ | 4.780115 kcal |
| 21 kJ | 5.01912 kcal |
| 22 kJ | 5.258126 kcal |
| 23 kJ | 5.497132 kcal |
| 24 kJ | 5.736138 kcal |
| 25 kJ | 5.975143 kcal |
| 26 kJ | 6.214149 kcal |
| 27 kJ | 6.453155 kcal |
| 28 kJ | 6.692161 kcal |
| 29 kJ | 6.931166 kcal |
| 30 kJ | 7.170172 kcal |
| 31 kJ | 7.409178 kcal |
| 32 kJ | 7.648184 kcal |
| 33 kJ | 7.887189 kcal |
| 34 kJ | 8.126195 kcal |
| 35 kJ | 8.365201 kcal |
| 36 kJ | 8.604207 kcal |
| 37 kJ | 8.843212 kcal |
| 38 kJ | 9.082218 kcal |
| 39 kJ | 9.321224 kcal |
| 40 kJ | 9.560229 kcal |
| 41 kJ | 9.799235 kcal |
| 42 kJ | 10.038241 kcal |
| 43 kJ | 10.277247 kcal |
| 44 kJ | 10.516252 kcal |
| 45 kJ | 10.755258 kcal |
| 46 kJ | 10.994264 kcal |
| 47 kJ | 11.23327 kcal |
| 48 kJ | 11.472275 kcal |
| 49 kJ | 11.711281 kcal |
| 50 kJ | 11.950287 kcal |
| 60 kJ | 14.340344 kcal |
| 70 kJ | 16.730402 kcal |
| 80 kJ | 19.120459 kcal |
| 90 kJ | 21.510516 kcal |
| 100 kJ | 23.900574 kcal |
Frequently asked questions
How many Kilocalories are in 1 Kilojoules?
1 kJ equals 0.23900574 kcal.
How do I convert Kilojoules to Kilocalories?
Multiply the kJ value by 0.23900574. Example: 25 kJ = 5.975143 kcal.
What is 2.5 kJ in kcal?
2.5 kJ = 0.59751434 kcal.
Is the kJ to kcal conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.