Convert Watt-hours to Kilojoules
Wh to kJ · energy conversion
What are watt-hours and kilojoules?
A watt-hour is the energy of one watt sustained for one hour, equal to 3,600 J. A kilojoule is 1,000 joules, used for food energy outside the US. For reference: a food Calorie is one kilocalorie (4,184 J), and home electricity is billed in kilowatt-hours.
How to convert watt-hours to kilojoules
1 Wh = 3.6 kJ. To convert, multiply the number of watt-hours by 3.6. For example, 5 Wh = 18 kJ, and 20 Wh = 72 kJ. To go the other way, multiply kilojoules by 0.277778 (since 1 kJ = 0.277778 Wh).
Watt-hours to Kilojoules conversion table
| Watt-hours (Wh) | Kilojoules (kJ) |
|---|---|
| 1 | 3.6 |
| 10 | 36 |
| 100 | 360 |
| 500 | 1,800 |
| 1,000 | 3,600 |
| 2,000 | 7,200 |
| 5,000 | 18,000 |
FAQ
What is 1 Wh in kJ?
1 Wh = 3.6 kJ. To convert any amount, multiply the number of watt-hours by 3.6.
How do I convert kilojoules back to watt-hours?
Go the other way: 1 kJ = 0.277778 Wh, so multiply kilojoules by 0.277778 to get watt-hours.
Is a watt-hour bigger than a kilojoule?
Yes — 1 Wh is the larger unit, equal to 3.6 kJ.
Are these energy conversions exact?
They use the standard internationally-defined conversion factors. Results are rounded to six significant figures for readability, which is accurate enough for everyday and most technical use.