Watt-hour to Joule Converter (Wh to J) + Formula
1 watt-hour equals 3,600 joules (J) — multiply watt-hours by 3,600 to convert. One watt is one joule per second, and an hour is 3,600 seconds, so running one watt for one hour delivers exactly 3,600 joules of energy. The conversion is exact.
The formula
Multiply watt-hours by 3,600 to get joules:
joules = watt-hours × 3600For example, 5 Wh × 3600 = 18,000 J. To reverse, divide joules by 3,600.
Conversion table
| Watt-hours (Wh) | Joules (J) |
|---|---|
| 1 | 3,600 |
| 2 | 7,200 |
| 5 | 18,000 |
| 10 | 36,000 |
| 25 | 90,000 |
| 50 | 180,000 |
| 100 | 360,000 |
| 500 | 1,800,000 |
| 1000 | 3,600,000 |
How to convert online
- Type the number of watt-hours into the first box.
- Read the equivalent joule value instantly in the second box.
- Type a joule value to convert back to watt-hours — it works both ways.
Use the Watt-hour to Joule Converter — free and instant in your browser.
Where this conversion is used
Watt-hours describe battery capacity and electricity use, while joules are the SI unit of energy used in physics and engineering. Converting between them is essential when comparing device energy consumption against work, heat, or mechanical energy calculations.
FAQ
How many joules are in a watt-hour?
Exactly 3,600 joules. So 10 Wh = 36,000 J.
What is the formula to convert watt-hours to joules?
Multiply the watt-hour value by 3,600. In symbols, J = Wh × 3600.
How do I convert joules back to watt-hours?
Divide joules by 3,600, or multiply by 0.00027778. So 7,200 J = 2 Wh.
Is the conversion exact?
Yes — 1 W × 3,600 s = 3,600 J exactly.
Related converters
- Joule to Watt-hour Converter
- Watt-hour to Kilojoule Converter
- Watt-hour to Calorie Converter
- Watt-hour to Kilowatt-hour Converter
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