The kilojoule
The kilojoule (kJ) equals exactly 1,000 joules. It is the standard unit on EU and many non-US nutrition labels — 1 dietary calorie ≈ 4.184 kJ. It also appears in industrial-process specifications and energy-storage ratings.
Kilojoules to Joules Converter
1 kJ = 1000 J
1 kilojoule equals 1000 joules. To convert kilojoules to joules, multiply the kilojoule value by 1000. For quick reference: 1 kJ = 1000 J, 5 kJ = 5000 J, 10 kJ = 10000 J, 100 kJ = 100000 J.
Formula
Joules = Kilojoules × 1000Quick
How to convert kilojoules to joules
Take your value
Start with your value in kilojoules.
Multiply by 1000
Multiply the kilojoule value by 1000. This is the exact conversion factor from kilojoules to joules.
Read the result
The product is your value in joules. For example, 5 kJ × 1000 = 5000 J.
Conversion formula
The exact factor from kilojoules to joules is 1000.
Joules = Kilojoules × 1000
Kilojoules to Joules conversion table
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| Kilojoules (kJ) | Joules (J) |
|---|---|
| 0.001 kJ | 1 J |
| 0.01 kJ | 10 J |
| 0.1 kJ | 100 J |
| 0.5 kJ | 500 J |
| 1 kJ | 1000 J |
| 1.5 kJ | 1500 J |
| 2 kJ | 2000 J |
| 5 kJ | 5000 J |
| 10 kJ | 10000 J |
| 20 kJ | 20000 J |
| 50 kJ | 50000 J |
| 100 kJ | 100000 J |
| 200 kJ | 200000 J |
| 250 kJ | 250000 J |
| 500 kJ | 500000 J |
| 1000 kJ | 1000000 J |
| 2000 kJ | 2000000 J |
| 2500 kJ | 2500000 J |
| 3600 kJ | 3600000 J |
| 5000 kJ | 5000000 J |
| 7500 kJ | 7500000 J |
| 10000 kJ | 10000000 J |
| 25000 kJ | 25000000 J |
| 50000 kJ | 50000000 J |
| 100000 kJ | 100000000 J |
| 250000 kJ | 250000000 J |
| 500000 kJ | 500000000 J |
| 1000000 kJ | 1000000000 J |
| 2000000 kJ | 2000000000 J |
| 3600000 kJ | 3600000000 J |
| 5000000 kJ | 5000000000 J |
| 10000000 kJ | 10000000000 J |
| 25000000 kJ | 25000000000 J |
| 50000000 kJ | 50000000000 J |
| 100000000 kJ | 100000000000 J |
| 250000000 kJ | 250000000000 J |
| 500000000 kJ | 500000000000 J |
| 1000000000 kJ | 1000000000000 J |
| 2000000000 kJ | 2000000000000 J |
| 5000000000 kJ | 5000000000000 J |
| 10000000000 kJ | 10000000000000 J |
| 20000000000 kJ | 20000000000000 J |
| 50000000000 kJ | 50000000000000 J |
| 100000000000 kJ | 100000000000000 J |
| 1000000000000 kJ | 1.0000 × 10^15 J |
| 10000000000000 kJ | 1.0000 × 10^16 J |
| 100000000000000 kJ | 1.0000 × 10^17 J |
| 1000000000000000 kJ | 1.0000 × 10^18 J |
| 10000000000000000 kJ | 1.0000 × 10^19 J |
| 100000000000000000 kJ | 1.0000 × 10^20 J |
Real-world reference
A medium banana provides about 450 kJ of food energy. A laptop battery typically stores 200–300 kJ. In joules, that gives you: 1 kJ = 1000 J, 10 kJ = 10000 J, 100 kJ = 100000 J.
Frequently asked questions
- How many joules are in 1 kilojoule?
- 1 kilojoule equals 1000 joules.
- How do I convert kilojoules to joules?
- Multiply the kilojoule value by 1000. So x kJ × 1000 = the equivalent in J.
- What is 5 kilojoules in joules?
- 5 kilojoules equals 5000 joules.
- What is 10 kilojoules in joules?
- 10 kilojoules equals 10000 joules.
- What is 100 kilojoules in joules?
- 100 kilojoules equals 100000 joules.
- How do I convert back from joules to kilojoules?
- Multiply the joule value by 0.001. For example, 1 J = 0.001 kJ.
- Is the kilojoule bigger than the joule?
- Yes. 1 kilojoule is larger than 1 joule — specifically 1000 times larger.
- Are these conversion factors exact?
- Yes. The factor of 1000 is derived directly from the SI definitions of kilojoule and joule.
About the kilojoule and the joule
The joule
The joule (J) is the SI derived unit of energy, work, and heat — defined as the energy transferred when a force of one newton acts over one meter. The joule is the standard unit in physics, chemistry, and most modern engineering documentation.