Kilocalories to Joules Converter
One Kilocalorie equals 4184 Joules (1 kcal = 4184 J). Multiply a Kilocalorie value by 4184 to get the equivalent in Joules. Use the calculator above for your value, or check the examples and reference table below.
Formula
J = kcal × 4184
Multiply the Kilocalorie value by 4184 to get the equivalent value in Joules.
Example Conversions
1 Kilocalorie (kcal)
4184 Joule (J)
5 Kilocalorie (kcal)
20920 Joule (J)
10 Kilocalorie (kcal)
41840 Joule (J)
25 Kilocalorie (kcal)
104600 Joule (J)
100 Kilocalorie (kcal)
418400 Joule (J)
Conversion Table
| Kilocalorie (kcal) | Joule (J) |
|---|---|
| 0.1 | 418.4 |
| 0.5 | 2092 |
| 1 | 4184 |
| 2 | 8368 |
| 5 | 20920 |
| 10 | 41840 |
| 25 | 104600 |
| 50 | 209200 |
| 100 | 418400 |
| 250 | 1046000 |
| 500 | 2092000 |
| 1000 | 4184000 |
How to Convert Manually
Use these steps to convert Kilocalorie values to Joule without the calculator.
- Write down the value in Kilocalorie (kcal) that you want to convert.
- Multiply that value by 4184.
- For example, 10 Kilocalories × 4184 = 41840 Joules.
- Label the result as Joule (J).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Kilocalorie and one Joule.
About Kilocalorie and Joule
The kilocalorie is 4,184 joules. It is the food 'Calorie' (capital C) on US nutrition labels. Diet tracking and exercise burn estimates use kilocalories. The joule is the SI derived unit of energy, the work done by a force of one newton over one meter. Physics, chemistry, and food labeling outside the US build on it. One Kilocalorie equals 4184 Joules (1 kcal = 4184 J). Kilocalorie is used in nutrition labels and diet tracking and in exercise calorie burn. Joule is used in physics and engineering calculations.
Precision and Rounding:Energy factors mix exact definitions (1 kWh = 3,600,000 J; 1 cal = 4.184 J thermochemical) with measured conventions (1 BTU ≈ 1,055.056 J). Nutrition and utility bills round to whole units; engineering heat calculations should keep the full factor until the final step.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15Kilocalories equals62760Joules.
15 kcal × 4184 = 62760 J
FAQ
How do I convert Kilocalorie to Joule?
Multiply the Kilocalorie value by 4184 to get the equivalent value in Joules.
What is the formula for Kilocalorie to Joule?
The formula is J = kcal × 4184.
How many Joules are in 1 Kilocalorie?
1 Kilocalorie equals 4184 Joules.
Can I convert Joule back to Kilocalorie?
Yes. 1 Joule equals 0.0002390057361 Kilocalories, and the related converter can reverse the calculation.
What are common names for Kilocalorie and Joule?
Kilocalorie is shown as kcal and may also be searched as kilocalorie, kilocalories, food calorie. Joule is shown as J and may also be searched as joule, joules.
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