Power and Energy
kcaltoGJ
Convert kilocalories (kcal) to gigajoules (GJ).
Factor1 kcal = 4.184e-6 GJ
Converter
kcal
Accepts numbers or expressions, e.g. 150 + 14.7
Result
GJ
Rendered to 6 significant figures.
Formula
Formula
GJ = kcal × 4.184e-6
Multiply any value in kilocalories by 4.184e-6 to obtain the value in gigajoules.
Worked example
Convert 1.00000e+6 kcal to GJ.
- 01Start with 1.00000e+6 kcal.
- 02Multiply by the conversion factor: 1.00000e+6 × 4.184e-6 = 4.184 GJ.
Result1.00000e+6 kcal = 4.184 GJ
Conversion table
| kcal | GJ |
|---|---|
| 1 | 4.184e-6 |
| 2 | 8.368e-6 |
| 5 | 2.092e-5 |
| 10 | 4.184e-5 |
| 20 | 8.368e-5 |
| 50 | 0.0002092 |
| 100 | 0.0004184 |
| 200 | 0.0008368 |
| 500 | 0.002092 |
| 1000 | 0.004184 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from kcal to GJ?
1 kcal equals 4.184e-6 GJ. To convert, multiply the value in kilocalories by 4.184e-6.
How do I convert 1 kcal to GJ?
1 kcal = 4.184e-6 GJ. For any value, multiply by 4.184e-6.
How do I convert GJ back to kcal?
Divide by the same factor — or equivalently, multiply by 239005.7. So 1 GJ = 239006 kcal.
When would I need to convert kilocalorie to gigajoule?
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).