Convert Kilojoules to Joules
One kilojoule equals 1,000 joules. Type any value to convert kilojoules to joules instantly — with a full reference table below.
Convert Kilojoules to Joules
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How to convert Kilojoules to Joules
To convert kilojoules to joules, multiply by 1,000. One kilojoule equals 1,000 J, and one joule equals 0.001 kJ.
- Take the value in kilojoules — for example 7.5 kJ.
- Multiply by 1,000 (the number of joules in one kilojoule).
- 7.5 × 1,000 = 7,500 J.
Shortcut: the factor is a power of ten, so just move the decimal point 3 places to the right.
Kilojoules to Joules conversion table
| Kilojoules | Joules |
|---|---|
| 1 kJ | 1,000 J |
| 2 kJ | 2,000 J |
| 5 kJ | 5,000 J |
| 10 kJ | 10,000 J |
| 20 kJ | 20,000 J |
| 50 kJ | 50,000 J |
| 100 kJ | 100,000 J |
| 200 kJ | 200,000 J |
| 500 kJ | 500,000 J |
| 1,000 kJ | 1,000,000 J |
| 2,000 kJ | 2,000,000 J |
| Joules | Kilojoules |
|---|---|
| 1 J | 0.001 kJ |
| 2 J | 0.002 kJ |
| 5 J | 0.005 kJ |
| 10 J | 0.01 kJ |
| 20 J | 0.02 kJ |
| 50 J | 0.05 kJ |
| 100 J | 0.1 kJ |
| 200 J | 0.2 kJ |
| 500 J | 0.5 kJ |
| 1,000 J | 1 kJ |
| 2,000 J | 2 kJ |
About converting Kilojoules to Joules
Kilojoules (kJ) and Joules (J) are both units of energy. The exact factor is 1 kJ = 1,000 J, so multiply by 1,000 to go from kilojoules to joules (or divide to go back).
The conversion runs entirely in your browser. Need the reverse? Use the Joules to Kilojoules converter, or the full unit converter for every unit at once.
Real-world energy in kilojoules and joules
| Example | Kilojoules | Joules |
|---|---|---|
| One food Calorie (kcal) | 4.184 kJ | 4,184 J |
| A 100 W bulb running for one hour | 360 kJ | 360,000 J |
| A smartphone battery (≈19 Wh) | ≈ 69.3 kJ | ≈ 69,300 J |
“≈” marks typical values; the rest are defined or measured figures.
The units
1,000 joules.
Used for: Food energy on labels in Australia and the EU.
The SI unit of energy: the work done by one newton over one metre.
Used for: Science and food labels (kJ).
The thermochemical calorie is exactly 4.184 J and a kilowatt-hour is exactly 3.6 MJ, so these factors are exact.