Convert watt-hours to joules
Enter a value in watt-hours (Wh) to get joules (J). One watt-hour is 3,600 joules; one joule is 0.00027778 watt-hours.
How to use the Watt-hour to joule
- Type the number of watt-hours.
- Click Convert.
- Read the result in joules, plus the same value in every other energy unit.
Wh to J formula
joules = watt-hours × 3,600. To go the other way, watt-hours = joules × 0.00027778 (see joules to watt-hours).
Worked example
12 Wh × 3,600 = 43,200 J.
Watt-hours to joules conversion table
| Watt-hours | Joules |
|---|---|
| 0.1 Wh | 360 J |
| 0.5 Wh | 1,800 J |
| 1 Wh | 3,600 J |
| 2 Wh | 7,200 J |
| 3 Wh | 10,800 J |
| 5 Wh | 18,000 J |
| 10 Wh | 36,000 J |
| 20 Wh | 72,000 J |
| 25 Wh | 90,000 J |
| 50 Wh | 180,000 J |
| 100 Wh | 360,000 J |
| 250 Wh | 900,000 J |
| 500 Wh | 1,800,000 J |
| 1,000 Wh | 3,600,000 J |
About the watt-hour
Battery capacity of phones and laptops.
About the joule
The SI unit of energy: one newton-metre, or one watt for one second.
Related conversions
Frequently asked questions
How many joules in a watt-hour?
3,600 joules.
How many watt-hours in a joule?
0.00027778 watt-hours.
Is the factor exact?
The factor 3,600 is derived from the units' exact definitions; only the display is rounded.
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Last updated 2026-09-23.