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 Attojoules
Convert Watt-hour (Wh) to Attojoule (aJ) instantly with an exact formula, conversion table, and FAQ.
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Convert watt hours (Wh) to attojoules (aJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
aJ = Wh × 3.600000000e+21
Results update instantly for Watt hours to Attojoules conversions.
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Formula
aJ = Wh × 3.600000000e+21
Wh = aJ × 2.777777778e-22
Conversion table
| 1 Wh | 3.600000e+21 aJ |
| 5 Wh | 1.800000e+22 aJ |
| 10 Wh | 3.600000e+22 aJ |
| 20 Wh | 7.200000e+22 aJ |
| 50 Wh | 1.800000e+23 aJ |
| 100 Wh | 3.600000e+23 aJ |
| 500 Wh | 1.800000e+24 aJ |
| 1000 Wh | 3.600000e+24 aJ |
Related conversions
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How the formula works
Both watt-hour and attojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in watt hours by 3.600000000e+21 to get attojoules. To reverse the conversion, multiply a attojoule value by 2.777777778e-22 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 Attojoule (aJ)?
A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
How do I convert watt hours to attojoules?
Multiply the watt-hour value by 3.600000000e+21 to get the equivalent in attojoules. For example, 5 Wh × 3.600000000e+21 = 1.800000e+22 aJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 3.600000000e+21 is an exact, non-rounded value.
Can I convert attojoules back to watt hours?
Yes. Divide the attojoule value by 3.600000000e+21, or multiply it by 2.777777778e-22, to get watt hours.
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About converting watt hours to attojoules
A watt-hour (Wh) is the energy delivered by one watt of power sustained for one hour, equal to 3,600 joules. A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
Use this calculator to move between watt hours and attojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.