Watt-hours (W·h) to Joules (J) Conversion
Watt-hours
The watt-hour (W·h) is a unit of energy equal to exactly 3,600 joules, defined as the energy consumed by a one-watt device operating for one hour. It is used in electrical engineering and consumer electronics for expressing battery capacities: a smartphone battery typically holds 10–20 Wh. In aviation, aircraft battery capacities are specified in watt-hours for international transport regulations (lithium batteries above 100 Wh face restrictions).
Joules
The joule (J) is the SI derived unit of energy, work, and heat, defined as the work done when a force of one newton displaces an object by one metre (J = N·m = kg·m²·s⁻²). Named after James Prescott Joule, who established the mechanical equivalent of heat in the 1840s, the joule unifies all forms of energy — mechanical, thermal, electrical, chemical, and nuclear — under one framework. One joule is small: lifting an apple (≈100 g) one metre requires about 1 joule, while a human at rest metabolises approximately 80 joules per second.
| Watt-hours (W·h) | Joules (J) |
|---|---|
| 0.1 W·h | 360 J |
| 1 W·h | 3600 J |
| 2 W·h | 7200 J |
| 3 W·h | 10800 J |
| 5 W·h | 18000 J |
| 10 W·h | 36000 J |
| 20 W·h | 72000 J |
| 30 W·h | 108000 J |
| 50 W·h | 180000 J |
| 100 W·h | 360000 J |
| 1000 W·h | 3600000 J |
Frequently Asked Questions (FAQ)
How many joules are in 1 watt-hours?
1 watt-hours (W·h) is exactly 3,600.00 joules (J).
How do I convert watt-hours to joules?
Multiply the value in watt-hours by 3,600.00 to get the result in joules. Or use the converter above — type any number and see the result instantly.