Convert joules to kilojoules
Joule (J) to kilojoule (kJ). One joule equals 0.001 kilojoules.
Formula
Joule to kilojoule conversion table
| Joules | Kilojoules | Kilojoules | Joules |
|---|---|---|---|
| 1 J | 0.001 kJ | 1 kJ | 1000 J |
| 2 J | 0.002 kJ | 2 kJ | 2000 J |
| 3 J | 0.003 kJ | 3 kJ | 3000 J |
| 5 J | 0.005 kJ | 5 kJ | 5000 J |
| 10 J | 0.01 kJ | 10 kJ | 10000 J |
| 20 J | 0.02 kJ | 20 kJ | 20000 J |
| 50 J | 0.05 kJ | 50 kJ | 50000 J |
| 100 J | 0.1 kJ | 100 kJ | 100000 J |
| 500 J | 0.5 kJ | 500 kJ | 500000 J |
| 1000 J | 1 kJ | 1000 kJ | 1000000 J |
To convert joules to kilojoules, divide the number of joules by 1000. One joule equals 0.001 kilojoules, and one kilojoule equals 1000 joules, so the relationship is fixed and exact. As a worked example, 10 J comes to 0.01 kJ. Enter your own figure in the converter above to get an instant answer, or use the swap button to flip the direction. This is a energy conversion, and like every tool on UnitGlide it runs locally in your browser with no account or upload required. The table further down shows a range of common joule values already worked out in kilojoules, plus the reverse kilojoule to joule direction, which is handy for quick reference or double-checking a result by hand.
Frequently asked questions
How many kilojoules are in a joule?
One joule equals 0.001 kilojoules. The ratio is constant, so you can multiply any number of joules by 0.001 to get kilojoules.
What is the formula to convert joules to kilojoules?
Use kilojoules = joules ÷ 1000. UnitGlide applies this exact formula for every value, so results stay accurate across the whole range.
How do I convert kilojoules back to joules?
Go the other way by using one kilojoule equals 1000 joules. You can also press the swap button in the converter above to flip the direction in one click.
Is this joule to kilojoule converter accurate?
Yes. It uses internationally defined SI conversion factors, as maintained by the BIPM, and all math runs in your browser so nothing is rounded away on a server. For everyday use the displayed precision is more than enough.