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.
Joules to Watt hours
Convert Joule (J) to Watt-hour (Wh) instantly with an exact formula, conversion table, and FAQ.
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Convert joules (J) to watt hours (Wh) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A watt-hour (Wh) is the energy delivered by one watt of power sustained for one hour, equal to 3,600 joules.
Wh = J × 0.0002777777778
Results update instantly for Joules to Watt hours conversions.
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Formula
Wh = J × 0.0002777777778
J = Wh × 3600
Conversion table
| 1 J | 0.000278 Wh |
| 5 J | 0.001389 Wh |
| 10 J | 0.002778 Wh |
| 20 J | 0.005556 Wh |
| 50 J | 0.013889 Wh |
| 100 J | 0.027778 Wh |
| 500 J | 0.138889 Wh |
| 1000 J | 0.277778 Wh |
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How the formula works
Both joule and watt-hour measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in joules by 0.0002777777778 to get watt hours. To reverse the conversion, multiply a watt-hour value by 3600 to get back to joules.
Frequently asked questions
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.
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.
How do I convert joules to watt hours?
Multiply the joule value by 0.0002777777778 to get the equivalent in watt hours. For example, 5 J × 0.0002777777778 = 0.001389 Wh.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 0.0002777777778 is an exact, non-rounded value.
Can I convert watt hours back to joules?
Yes. Divide the watt-hour value by 0.0002777777778, or multiply it by 3600, to get joules.
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About converting joules to watt hours
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. A watt-hour (Wh) is the energy delivered by one watt of power sustained for one hour, equal to 3,600 joules.
Use this calculator to move between joules and watt hours accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.