A watt-hour (Wh) is the energy delivered by one watt of power sustained for one hour, equal to 3,600 joules.
Watt hours to Joules
Convert Watt-hour (Wh) to Joule (J) instantly with an exact formula, conversion table, and FAQ.
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Convert watt hours (Wh) to joules (J) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
J = Wh × 3600
Results update instantly for Watt hours to Joules conversions.
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Formula
J = Wh × 3600
Wh = J × 0.0002777777778
Conversion table
| 1 Wh | 3600 J |
| 5 Wh | 18000 J |
| 10 Wh | 36000 J |
| 20 Wh | 72000 J |
| 50 Wh | 180000 J |
| 100 Wh | 360000 J |
| 500 Wh | 1.800000e+06 J |
| 1000 Wh | 3.600000e+06 J |
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How the formula works
Both watt-hour and joule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in watt hours by 3600 to get joules. To reverse the conversion, multiply a joule value by 0.0002777777778 to get back to watt hours.
Frequently asked questions
What is Watt-hour (Wh)?
A watt-hour (Wh) is the energy delivered by one watt of power sustained for one hour, equal to 3,600 joules.
What is Joule (J)?
The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
How do I convert watt hours to joules?
Multiply the watt-hour value by 3600 to get the equivalent in joules. For example, 5 Wh × 3600 = 18000 J.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 3600 is an exact, non-rounded value.
Can I convert joules back to watt hours?
Yes. Divide the joule value by 3600, or multiply it by 0.0002777777778, to get watt hours.
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About converting watt hours to joules
A watt-hour (Wh) is the energy delivered by one watt of power sustained for one hour, equal to 3,600 joules. The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
Use this calculator to move between watt hours and joules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.