How kilowatt-hours and kilojoules are converted
1 kWh = 3,600 kJ. In reverse, 7,200 kJ = 2 kWh.
kilojoules = kilowatt-hours × 3600; kilowatt-hours = kilojoules ÷ 3600
- Multiply kilowatt-hours by 3600 to find kilojoules.
- Reverse the calculation to convert kilojoules back to kilowatt-hours.
- Only the displayed values are rounded. The conversion uses the full unit factor.
Worked example: 1 kWh = 3,600 kJ. In reverse, 7,200 kJ = 2 kWh.
Common kilowatt-hours to kilojoules values
| Kilowatt-hours | Kilojoules (kJ) |
|---|---|
| 1 kWh | 3,600 kJ |
| 10 kWh | 36,000 kJ |
| 100 kWh | 360,000 kJ |
| 5 kWh | 18,000 kJ |
Swipe the table sideways to see the rest.
Results use the same exact factors as the calculator.
Things to consider
- Check whether a food label uses kcal or kJ before comparing values.
- One dietary Calorie is one kilocalorie, equal to 4.184 kJ.
- Power in kilowatts needs a duration in hours to calculate energy in kWh.
- Negative amounts can represent an energy change, such as heat leaving a system.
Frequently asked questions
How do I convert kilowatt-hours to kilojoules?
Multiply by 3600. 1 kWh = 3,600 kJ. In reverse, 7,200 kJ = 2 kWh.
Can I convert kilojoules back to kilowatt-hours?
Yes. Choose the reverse direction. Divide by 3600.
Are food Calories the same as small calories?
No. A food Calorie means one kilocalorie (kcal), equal to 1,000 small calories (cal). This converter uses thermochemical calories: 1 kcal = 4.184 kJ.
Is a kilowatt-hour the same as a kilowatt?
No. Kilowatts measure power. Kilowatt-hours measure energy. At constant power, 1 kW for 1 hour uses 1 kWh.
Results are estimates for general information only, not financial, medical or professional advice.