How to convert kilocalories to joules
J = kcal × 4,184Multiply the value in kilocalories by 4,184. To go the other way, multiply by 0.0002390057361 (or divide by 4,184).
A kilocalorie is larger than a joule: one kilocalorie contains 4,184 joules.
Worked examples
- 1 kilocalorie (food Calorie)1 kcal × 4,184 = 4,184 J
- 5 kilocalories5 kcal × 4,184 = 20,920 J
- 10 kilocalories10 kcal × 4,184 = 41,840 J
- 20 kilocalories20 kcal × 4,184 = 83,680 J
- 100 kilocalories100 kcal × 4,184 = 418,400 J
Kilocalories to joules conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Kilocalories (kcal) | Joules (J) |
|---|---|
| 0.1 kcal | 418.4 J |
| 0.25 kcal | 1,046 J |
| 0.5 kcal | 2,092 J |
| 1 kcal | 4,184 J |
| 2 kcal | 8,368 J |
| 3 kcal | 12,552 J |
| 4 kcal | 16,736 J |
| 5 kcal | 20,920 J |
| 6 kcal | 25,104 J |
| 7 kcal | 29,288 J |
| 8 kcal | 33,472 J |
| 9 kcal | 37,656 J |
| 10 kcal | 41,840 J |
| Kilocalories (kcal) | Joules (J) |
|---|---|
| 12 kcal | 50,208 J |
| 15 kcal | 62,760 J |
| 20 kcal | 83,680 J |
| 25 kcal | 104,600 J |
| 30 kcal | 125,520 J |
| 40 kcal | 167,360 J |
| 50 kcal | 209,200 J |
| 75 kcal | 313,800 J |
| 100 kcal | 418,400 J |
| 250 kcal | 1,046,000 J |
| 500 kcal | 2,092,000 J |
| 1,000 kcal | 4,184,000 J |
About the units
Kilocalorie (kcal)
One thousand small calories, or 4,184 J. The “Calories” on nutrition labels are kilocalories.
Joule (J)
The SI unit of energy: the work done by a force of one newton over one metre, or one watt for one second. Lifting an apple by one metre takes about 1 J.
Frequently asked questions
How many joules are in one kilocalorie?
There are 4,184 joules in one kilocalorie, and this value is exact by definition.
How do I convert kilocalories to joules?
Multiply the number of kilocalories by 4,184. For example, 10 kcal × 4,184 = 41,840 J.
How many kilocalories are in one joule?
One joule equals 0.0002390057361 kilocalories. That is the reverse factor, 1 ÷ 4,184.
What is 10 kilocalories in joules?
10 kcal = 41,840 J.
Is this kcal to J converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.