Power and Energy
JtokJ
Convert joules (J) to kilojoules (kJ).
Factor1 J = 0.001 kJ
Converter
J
Accepts numbers or expressions, e.g. 150 + 14.7
Result
kJ
Rendered to 6 significant figures.
Formula
Formula
kJ = J × 0.001
Multiply any value in joules by 0.001 to obtain the value in kilojoules.
Worked example
Convert 5000 J to kJ.
- 01Start with 5000 J.
- 02Multiply by the conversion factor: 5000 × 0.001 = 5 kJ.
Result5000 J = 5 kJ
Conversion table
| J | kJ |
|---|---|
| 1 | 0.001 |
| 2 | 0.002 |
| 5 | 0.005 |
| 10 | 0.01 |
| 20 | 0.02 |
| 50 | 0.05 |
| 100 | 0.1 |
| 200 | 0.2 |
| 500 | 0.5 |
| 1000 | 1 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from J to kJ?
1 J equals 0.001 kJ. To convert, multiply the value in joules by 0.001.
How do I convert 1 J to kJ?
1 J = 0.001 kJ. For any value, multiply by 0.001.
How do I convert kJ back to J?
Divide by the same factor — or equivalently, multiply by 1000. So 1 kJ = 1000 J.
When would I need to convert joule 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).