Kilocalorie to Joule Converter
One Kilocalorie equals 4184 Joule (1 kcal = 4184 J). Multiply a Kilocalorie value by 4184 to get the equivalent in Joule. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
J = kcal × 4184
Multiply the Kilocalorie value by 4184 to get the equivalent value in Joule.
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 Kilocalorie × 4184 = 41840 Joule.
- 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 — 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 Joule (1 kcal = 4184 J). Kilocalorie to Joule conversion comes up most often in nutrition labels and diet tracking and in exercise calorie burn, typically when figures need restating for 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
15 Kilocalorie equals 62760 Joule.
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 Joule.
What is the formula for Kilocalorie to Joule?
The formula is J = kcal × 4184.
How many Joule are in 1 Kilocalorie?
1 Kilocalorie equals 4184 Joule.
Can I convert Joule back to Kilocalorie?
Yes. 1 Joule equals 0.0002390057361 Kilocalorie, 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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