Convert Joule to Watt-hour

One J equals 0.0002777777778 Wh. This converter allows you to easily convert between Joule and Watt-hour in real time.

Formula

J × 0.0002777777778 = Wh

Example: 1 J = 0.0002777777778 Wh

What is Joule?

The joule is the SI unit of energy, named after English physicist James Prescott Joule. One joule equals the work done by a force of one newton moving an object one meter, or the energy used by one watt of power for one second. Food energy labels in many countries show kilojoules alongside calories. In physics, the joule unifies mechanical, thermal, and electrical energy into a single consistent unit.

What is Watt-hour?

The watt-hour is a unit of energy equal to 3,600 joules, representing the energy used by one watt of power over one hour. It is commonly used for portable battery capacities; a typical power bank rated at 5,000 mAh at 3.7 V holds about 18.5 Wh. Airline regulations for lithium-ion batteries are also specified in watt-hours, with batteries under 100 Wh generally permitted in carry-on luggage.