Power and Energy
kcaltokJ
Convert kilocalories (kcal) to kilojoules (kJ).
Factor1 kcal = 4.184 kJ
Converter
kcal
Accepts numbers or expressions, e.g. 150 + 14.7
Result
kJ
Rendered to 6 significant figures.
Formula
Formula
kJ = kcal × 4.184
Multiply any value in kilocalories by 4.184 to obtain the value in kilojoules.
Worked example
Convert 1 kcal to kJ.
- 01Start with 1 kcal.
- 02Multiply by the conversion factor: 1 × 4.184 = 4.184 kJ.
Result1 kcal = 4.184 kJ
Conversion table
| kcal | kJ |
|---|---|
| 1 | 4.184 |
| 2 | 8.368 |
| 5 | 20.92 |
| 10 | 41.84 |
| 20 | 83.68 |
| 50 | 209.2 |
| 100 | 418.4 |
| 200 | 836.8 |
| 500 | 2092 |
| 1000 | 4184 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from kcal to kJ?
1 kcal equals 4.184 kJ. To convert, multiply the value in kilocalories by 4.184.
How do I convert 1 kcal to kJ?
1 kcal = 4.184 kJ. For any value, multiply by 4.184.
How do I convert kJ back to kcal?
Divide by the same factor — or equivalently, multiply by 0.2390057. So 1 kJ = 0.239006 kcal.
When would I need to convert kilocalorie to kilojoule?
Energy conversions are needed when reconciling fuel/electrical billing, calculating thermal duties, and aligning calorimetry or HHV/LHV figures across data sources.
Is the conversion exact?
The factor shown is precise to at least 7 significant figures. For most process-engineering work this is far better than instrument accuracy. For metrology or trade applications, refer to the relevant national standard (NIST, BIPM, ISO 80000).