How to convert kilojoules to joules
To convert kilojoules to joules, multiply the value by the conversion factor 1,000. To go the other way, multiply by 0.001 (or divide by 1,000).
Worked example: 25 kJ to J
- Write the value: 25 kJ
- Multiply by 1,000: 25 × 1,000
- Result: 25,000 J
Kilojoule to Joule conversion table
Quick reference values, rounded to 6 significant digits.
| Kilojoule (kJ) | Joule (J) |
|---|---|
| 0.1 kJ | 100 J |
| 0.25 kJ | 250 J |
| 0.5 kJ | 500 J |
| 1 kJ | 1,000 J |
| 2 kJ | 2,000 J |
| 3 kJ | 3,000 J |
| 4 kJ | 4,000 J |
| 5 kJ | 5,000 J |
| 6 kJ | 6,000 J |
| 7 kJ | 7,000 J |
| 8 kJ | 8,000 J |
| 9 kJ | 9,000 J |
| 10 kJ | 10,000 J |
| 12 kJ | 12,000 J |
| 15 kJ | 15,000 J |
| 20 kJ | 20,000 J |
| 25 kJ | 25,000 J |
| 30 kJ | 30,000 J |
| 40 kJ | 40,000 J |
| 50 kJ | 50,000 J |
| 75 kJ | 75,000 J |
| 100 kJ | 100,000 J |
| 250 kJ | 250,000 J |
| 500 kJ | 500,000 J |
| 1,000 kJ | 1,000,000 J |
Joule to Kilojoule
| J | kJ |
|---|---|
| 1 J | 0.001 kJ |
| 5 J | 0.005 kJ |
| 10 J | 0.01 kJ |
| 50 J | 0.05 kJ |
| 100 J | 0.1 kJ |
1 Kilojoule in other energy units
About Kilojoule and Joule
What is a kilojoule (kJ)?
A kilojoule equals 1,000 joules, used on food labels.
What is a joule (J)?
The joule is the SI unit of energy.
Where kilojoule to joule conversion is used
Energy conversions are needed for electricity bills, food calories, heating, batteries and physics. Converting between kilojoules and joules is especially common when you compare products, read foreign specifications, or fill in forms that expect a specific unit.
Need every unit at once? Use the full Energy Converter.
Frequently asked questions
How many joules are in 1 kilojoule?
1 Kilojoule equals 1,000 J.
How do I convert kilojoules to joules?
Multiply the number of kilojoules by 1,000. For example, 25 kJ × 1,000 = 25,000 J.
What is 25 kJ in J?
25 kJ = 25,000 J.
How many kilojoules are in 1 joule?
1 Joule equals 0.001 kJ. Use the Joules to kJ converter for the reverse direction.
Is this Kilojoule to Joule converter accurate?
Yes. It uses exact internationally defined conversion factors, calculated with full floating-point precision. Results are displayed rounded for readability.