This converter turns kilojoules into kilocalories instantly, using the exact factor 1 kilojoule = 0.2390057361 kilocalories. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
The food-energy unit on labels outside the United States. The dietary Calorie shown on US nutrition labels.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
kilojoules- The amount you are converting, measured in kilojoules
0.2390057361- The exact number of kilocalories in one kilojoule
kilocalories- The converted result
How it works, step by step
- Enter the number of kilojoules you want to convert.
- The value is multiplied by 0.2390057361, the exact conversion factor.
- The result is displayed in kilocalories, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 kilojoules
Multiply 5 by 0.23900574. That gives 1.195 kilocalories. A quick sanity check: one kilojoule is smaller than one kilocalorie, so the number should get smaller — and it does.
Converting 72 kilojoules
72 × 0.23900574 = 17.2084 kilocalories. Working backwards, 17.2084 ÷ 0.23900574 returns 72 kilojoules, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many kilocalories are in one kilojoule?
Exactly 0.2390057361. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert kilojoules to kilocalories?
Kilocalories = kilojoules × 0.2390057361. To reverse it, divide instead: kilojoules = kilocalories ÷ 0.2390057361, which is the same as multiplying by 4.184.
Is the kilojoule bigger than the kilocalorie?
No. One kilojoule is only 0.239006 of a kilocalorie, so the kilocalorie is the larger unit.
Why does my answer differ slightly from other kilojoules to kilocalories converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a kilojoule?
The food-energy unit on labels outside the United States.
What is a kilocalorie?
The dietary Calorie shown on US nutrition labels.
Kilojoules to kilocalories reference table
| Kilojoules | Kilocalories |
|---|---|
| 0.5 kJ | 0.119503 kcal |
| 1 kJ | 0.239006 kcal |
| 2 kJ | 0.478011 kcal |
| 3 kJ | 0.717017 kcal |
| 5 kJ | 1.195 kcal |
| 10 kJ | 2.3901 kcal |
| 15 kJ | 3.5851 kcal |
| 20 kJ | 4.7801 kcal |
| 25 kJ | 5.9751 kcal |
| 50 kJ | 11.9503 kcal |
| 75 kJ | 17.9254 kcal |
| 100 kJ | 23.9006 kcal |
| 250 kJ | 59.7514 kcal |
| 500 kJ | 119.5029 kcal |
| 1000 kJ | 239.0057 kcal |
Exact factor: 1 kilojoule = 0.2390057361 kilocalories. Values rounded for display.