Kilocalories to Kilojoules Converter
One Kilocalorie equals 4.184 Kilojoules (1 kcal = 4.184 kJ). Multiply a Kilocalorie value by 4.184 to get the equivalent in Kilojoules. Enter your value in the calculator above. The formula and examples below show how to calculate it by hand.
Formula
kJ = kcal × 4.184
Multiply the Kilocalorie value by 4.184 to get the equivalent value in Kilojoules.
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 Kilocalories × 4.184 = 41.84 Kilojoules.
- 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. It is 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 Kilojoules (1 kcal = 4.184 kJ). Kilocalorie is used in nutrition labels and diet tracking and in exercise calorie burn. Kilojoule is used in 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
15Kilocalories equals62.76Kilojoules.
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 Kilojoules.
What is the formula for Kilocalorie to Kilojoule?
The formula is kJ = kcal × 4.184.
How many Kilojoules are in 1 Kilocalorie?
1 Kilocalorie equals 4.184 Kilojoules.
Can I convert Kilojoule back to Kilocalorie?
Yes. 1 Kilojoule equals 0.2390057361 Kilocalories, 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.
Was this page helpful?
Let us know if this converter met your needs.