Watt-hour (Wh)
The watt-hour (Wh) is the energy of one watt for one hour, 3600 J. It is used for battery capacity.
Symbol: Wh
Quantity: energy, work and heat
SI relation: 1 Wh = 3600 J (exact)
Derivation: 1 Wh = 1 W × 3600 s = 3600 J
Exact: yes, by definition
Typical uses
- Battery capacity (phone ≈ 15 Wh; airline limit 100 Wh per power bank)
- Small appliance energy use
- Solar panel daily output
Convert watt-hours to other units
| Conversion | 1 Wh equals | Reverse |
|---|---|---|
| watt-hour to joule | 3600 J | joule to watt-hour |
| watt-hour to kilojoule | 3.6 kJ | kilojoule to watt-hour |
| watt-hour to kilocalorie | 0.8604206501 kcal | kilocalorie to watt-hour |
| watt-hour to kilowatt-hour | 0.001 kWh | kilowatt-hour to watt-hour |
| watt-hour to BTU | 3.412141633 BTU | BTU to watt-hour |
| watt-hour to megajoule | 0.0036 MJ | megajoule to watt-hour |
| watt-hour to calorie | 860.4206501 cal | calorie to watt-hour |
| watt-hour to therm | 0.00003412956341 thm | therm to watt-hour |
| watt-hour to electronvolt | 2.246943267 × 10²² eV | electronvolt to watt-hour |
| watt-hour to foot-pound | 2655.223737 ft·lbf | foot-pound to watt-hour |
| watt-hour to erg | 36000000000 erg | erg to watt-hour |
Open the Energy Converter to convert any value between all units.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "watt hour (W·h)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Watt-hour (Wh). Retrieved October 17, 2026, from https://scientificconverters.com/units/watt-hour/
IEEE
Scientific Converters, "Watt-hour (Wh)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/watt-hour/