Convert Watt Hour to Kilojoule
Use this free converter to change watt hours (Wh) into kilojoules (kJ). Watt hour and kilojoule both measure energy. As a quick reference, 1 Wh equals 3.6 kJ, and 1 kJ equals 0.27777778 Wh.
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Kilojoule (kJ)
3.6
1 Wh = 3.6 kJ
Energy conversion table
| Watt Hour | Kilojoule |
|---|---|
| 0.01 | 0.036 |
| 0.1 | 0.36 |
| 0.5 | 1.8 |
| 1 | 3.6 |
| 2 | 7.2 |
| 3 | 10.8 |
| 5 | 18 |
| 10 | 36 |
| 20 | 72 |
| 25 | 90 |
| 50 | 180 |
| 100 | 360 |
| 1,000 | 3600 |
How to convert Watt Hour to Kilojoule
Multiply the watt hour value by 3.6 to get kilojoules.
- Enter the number of watt hours you want to convert.
- The converter instantly shows the equivalent value in kilojoules.
- Worked example: 15 Wh × 3.6 = 54 kJ.
- Use the swap button to reverse the conversion (kilojoule to watt hour).
About these units
Watt Hour (Wh)
- Definition
- A watt-hour (Wh) is the energy of one watt sustained for one hour, equal to 3,600 joules.
- History
- It arose with the electricity industry as a practical billing unit.
- Current use
- Watt-hours rate batteries and small energy stores.
Kilojoule (kJ)
- Definition
- A kilojoule (kJ) is 1,000 joules, a practical size for food energy and mechanical work.
- History
- It is a metric multiple of the joule.
- Current use
- Kilojoules express food energy on nutrition labels in many countries.
Frequently asked questions
How many kilojoules are in a watt hour?
There are 3.6 kJ in 1 Wh. To convert, multiply the number of watt hours by 3.6.
How do I convert watt hours to kilojoules?
Multiply the watt hour value by 3.6 to get kilojoules. For example, 10 Wh = 36 kJ.
Is this watt hour-to-kilojoule converter free?
Yes. This converter is completely free, runs entirely in your browser, and requires no sign-up. Your inputs never leave your device.
Convert Watt Hour to other energy units
| Unit | 1 Watt Hour equals |
|---|---|
| Joule (J) | 3600 J |
| Kilojoule (kJ) | 3.6 kJ |
| Calorie (cal) | 860.42065 cal |
| Kilocalorie (kcal) | 0.86042065 kcal |
| Kilowatt Hour (kWh) | 0.001 kWh |
| Electronvolt (eV) | 2.2469e+22 eV |
| British Thermal Unit (BTU) | 3.4121416 BTU |
| Foot-Pound (ft·lb) | 2655.2237 ft·lb |