Joule [J] to Watt-hour [Wh] Converter

Quick Reference

1 Joule (J) = 0.0002777777778 Watt-hour (Wh)

1 Watt-hour (Wh) = 3600 Joule (J)

How to Convert Joule to Watt-hour

1 J = 0.0002777777777777778 Wh
1 Wh = 3600 J

To convert Joule to Watt-hour, divide the value by 3600 (equivalently, multiply by 0.0002777777778). To convert Watt-hour back to Joule, multiply by 3600.

Example: convert 10 J to Wh:
10 J = 10 x 0.0002777777777777778 = 0.002777777777777778 Wh

↔ Convert Watt-hour to Joule

Joule

Definition: The joule (symbol: J) is the SI derived unit of energy. It is defined as the energy transferred to (or work done on) an object when a force of one newton acts on that object in the direction of its motion through a distance of one metre (1 newton metre or N⋅m).

History/origin: Named after James Prescott Joule, an English physicist. Joule experimentally determined the mechanical equivalent of heat.

Current use: Used universally in science and engineering to quantify energy, work, and heat. Examples include kinetic energy, potential energy, and heat content of materials.

Watt-hour

Definition: A watt-hour (symbol Wh) is a unit of energy equal to one watt of power sustained for one hour. It is commonly used to measure electrical energy consumption.

History/origin: The watt-hour is derived from the watt, the SI unit of power, and the hour, a unit of time. It was developed alongside the increasing use of electricity in the late 19th and early 20th centuries.

Current use: Watt-hours are commonly used to measure the energy capacity of batteries, the energy consumption of household appliances, and the amount of electricity generated or consumed by power plants and consumers.

Joule to Watt-hour Conversion Table

Joule [J]	Watt-hour [Wh]
1 J	0.0002777777777777778 Wh
2 J	0.0005555555555555556 Wh
5 J	0.001388888888888889 Wh
10 J	0.002777777777777778 Wh
20 J	0.005555555555555556 Wh
50 J	0.013888888888888888 Wh
100 J	0.027777777777777776 Wh
200 J	0.05555555555555555 Wh
500 J	0.1388888888888889 Wh
1000 J	0.2777777777777778 Wh

Common pairs of Energy

Watt-hour

Watt-hour to Milliwatt-hour Watt-hour to Kilowatt-hour Watt-hour to Megawatt-hour Watt-hour to Gigawatt-hour Watt-hour to Joule

Milliwatt-hour

Milliwatt-hour to Watt-hour Milliwatt-hour to Kilowatt-hour Milliwatt-hour to Megawatt-hour Milliwatt-hour to Gigawatt-hour Milliwatt-hour to Joule

Kilowatt-hour

Kilowatt-hour to Watt-hour Kilowatt-hour to Milliwatt-hour Kilowatt-hour to Megawatt-hour Kilowatt-hour to Gigawatt-hour Kilowatt-hour to Joule

Megawatt-hour

Megawatt-hour to Watt-hour Megawatt-hour to Milliwatt-hour Megawatt-hour to Kilowatt-hour Megawatt-hour to Gigawatt-hour Megawatt-hour to Joule

Gigawatt-hour

Gigawatt-hour to Watt-hour Gigawatt-hour to Milliwatt-hour Gigawatt-hour to Kilowatt-hour Gigawatt-hour to Megawatt-hour Gigawatt-hour to Joule

Joule

Joule to Watt-hour Joule to Milliwatt-hour Joule to Kilowatt-hour Joule to Megawatt-hour Joule to Gigawatt-hour

Kilojoule

Kilojoule to Watt-hour Kilojoule to Milliwatt-hour Kilojoule to Kilowatt-hour Kilojoule to Megawatt-hour Kilojoule to Gigawatt-hour

Joule [J] to Watt-hour [Wh] Converter

To convert Joule to Watt-hour, enter your value in the J field above and the result in Wh will appear instantly. You can also use the conversion factor shown in the table on this page to calculate manually. The formula is always the same: multiply your J value by the fixed conversion ratio to get the equivalent in Wh.

Our Joule to Watt-hour converter uses standardized conversion factors defined by international scientific and metrological organizations. All calculations are performed with full floating-point precision. You can also choose how many decimal places to display in the result, so you get exactly the level of detail you need.

Yes, absolutely. Simply swap the source and destination units in the converter — select Wh as your input unit and J as your output unit. The same precision and standardized conversion factor applies in both directions.

Converting between Joule and Watt-hour comes up regularly in engineering, scientific research, construction, and everyday tasks that involve measurements from different unit systems. Our converter eliminates the risk of manual calculation errors and saves time whenever you need to switch between these two units.

Yes, the Joule to Watt-hour converter is completely free. No account or registration is required, and there are no usage limits. It works on any device — smartphones, tablets, and desktop computers — directly in your browser.

Joule and Watt-hour are both units used to measure the same physical quantity, but they belong to different measurement systems or represent different scales. The mathematical relationship between them is fixed and constant, which is what makes accurate conversion possible. Scroll up to see the exact conversion factor, formula, and a reference table for common values.

Joule [J] to Watt-hour [Wh] Converter

Quick Reference

1 Joule (J) = 0.0002777777778 Watt-hour (Wh)

1 Watt-hour (Wh) = 3600 Joule (J)

How to Convert Joule to Watt-hour

1 J = 0.0002777777777777778 Wh
1 Wh = 3600 J

To convert Joule to Watt-hour, divide the value by 3600 (equivalently, multiply by 0.0002777777778). To convert Watt-hour back to Joule, multiply by 3600.

Example: convert 10 J to Wh:
10 J = 10 x 0.0002777777777777778 = 0.002777777777777778 Wh

↔ Convert Watt-hour to Joule

Joule

History/origin: Named after James Prescott Joule, an English physicist. Joule experimentally determined the mechanical equivalent of heat.

Current use: Used universally in science and engineering to quantify energy, work, and heat. Examples include kinetic energy, potential energy, and heat content of materials.

Watt-hour

Definition: A watt-hour (symbol Wh) is a unit of energy equal to one watt of power sustained for one hour. It is commonly used to measure electrical energy consumption.

Joule to Watt-hour Conversion Table

Joule [J]	Watt-hour [Wh]
1 J	0.0002777777777777778 Wh
2 J	0.0005555555555555556 Wh
5 J	0.001388888888888889 Wh
10 J	0.002777777777777778 Wh
20 J	0.005555555555555556 Wh
50 J	0.013888888888888888 Wh
100 J	0.027777777777777776 Wh
200 J	0.05555555555555555 Wh
500 J	0.1388888888888889 Wh
1000 J	0.2777777777777778 Wh

Common pairs of Energy

Watt-hour

Watt-hour to Milliwatt-hour Watt-hour to Kilowatt-hour Watt-hour to Megawatt-hour Watt-hour to Gigawatt-hour Watt-hour to Joule

Milliwatt-hour

Milliwatt-hour to Watt-hour Milliwatt-hour to Kilowatt-hour Milliwatt-hour to Megawatt-hour Milliwatt-hour to Gigawatt-hour Milliwatt-hour to Joule

Kilowatt-hour

Kilowatt-hour to Watt-hour Kilowatt-hour to Milliwatt-hour Kilowatt-hour to Megawatt-hour Kilowatt-hour to Gigawatt-hour Kilowatt-hour to Joule

Megawatt-hour

Megawatt-hour to Watt-hour Megawatt-hour to Milliwatt-hour Megawatt-hour to Kilowatt-hour Megawatt-hour to Gigawatt-hour Megawatt-hour to Joule

Gigawatt-hour

Gigawatt-hour to Watt-hour Gigawatt-hour to Milliwatt-hour Gigawatt-hour to Kilowatt-hour Gigawatt-hour to Megawatt-hour Gigawatt-hour to Joule

Joule

Joule to Watt-hour Joule to Milliwatt-hour Joule to Kilowatt-hour Joule to Megawatt-hour Joule to Gigawatt-hour

Kilojoule

Kilojoule to Watt-hour Kilojoule to Milliwatt-hour Kilojoule to Kilowatt-hour Kilojoule to Megawatt-hour Kilojoule to Gigawatt-hour