Kilocalorie to Kilojoule Converter
One Kilocalorie equals 4.184 Kilojoule (1 kcal = 4.184 kJ). Multiply a Kilocalorie value by 4.184 to get the equivalent in Kilojoule. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
kJ = kcal × 4.184
Multiply the Kilocalorie value by 4.184 to get the equivalent value in Kilojoule.
Example Conversions
1 Kilocalorie (kcal)
4.184 Kilojoule (kJ)
5 Kilocalorie (kcal)
20.92 Kilojoule (kJ)
10 Kilocalorie (kcal)
41.84 Kilojoule (kJ)
25 Kilocalorie (kcal)
104.6 Kilojoule (kJ)
100 Kilocalorie (kcal)
418.4 Kilojoule (kJ)
Conversion Table
| Kilocalorie (kcal) | Kilojoule (kJ) |
|---|---|
| 0.1 | 0.4184 |
| 0.5 | 2.092 |
| 1 | 4.184 |
| 2 | 8.368 |
| 5 | 20.92 |
| 10 | 41.84 |
| 25 | 104.6 |
| 50 | 209.2 |
| 100 | 418.4 |
| 250 | 1046 |
| 500 | 2092 |
| 1000 | 4184 |
How to Convert Manually
Use these steps to convert Kilocalorie values to Kilojoule without the calculator.
- Write down the value in Kilocalorie (kcal) that you want to convert.
- Multiply that value by 4.184.
- For example, 10 Kilocalorie × 4.184 = 41.84 Kilojoule.
- Label the result as Kilojoule (kJ).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Kilocalorie and one Kilojoule.
About Kilocalorie and Kilojoule
The kilocalorie is 4,184 joules — the food 'Calorie' (capital C) on US nutrition labels. Diet tracking and exercise burn estimates use kilocalories. The kilojoule is 1,000 joules. Food energy in Australia, Europe, and most metric countries is labeled in kilojoules alongside or instead of calories. One Kilocalorie equals 4.184 Kilojoule (1 kcal = 4.184 kJ). Kilocalorie to Kilojoule conversion comes up most often in nutrition labels and diet tracking and in exercise calorie burn, typically when figures need restating for food labels outside the US.
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 62.76 Kilojoule.
15 kcal × 4.184 = 62.76 kJ
FAQ
How do I convert Kilocalorie to Kilojoule?
Multiply the Kilocalorie value by 4.184 to get the equivalent value in Kilojoule.
What is the formula for Kilocalorie to Kilojoule?
The formula is kJ = kcal × 4.184.
How many Kilojoule are in 1 Kilocalorie?
1 Kilocalorie equals 4.184 Kilojoule.
Can I convert Kilojoule back to Kilocalorie?
Yes. 1 Kilojoule equals 0.2390057361 Kilocalorie, and the related converter can reverse the calculation.
What are common names for Kilocalorie and Kilojoule?
Kilocalorie is shown as kcal and may also be searched as kilocalorie, kilocalories, food calorie. Kilojoule is shown as kJ and may also be searched as kilojoule, kilojoules.
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