How to convert watt-hours to joules
To convert a measurement in watt-hours to joules, multiply the value by 3,600. The conversion factor comes from the relationship between both units and the joule.
For example, to convert 5 Wh to joules: 5 × 3,600 = 18,000 J.
What is a watt-hour?
A watt-hour is the energy delivered by one watt of power over one hour, equal to 3,600 joules. The watt-hour emerged with the electrical industry as a practical measure of energy use over time. It underpins the kilowatt-hour that appears on electricity bills worldwide.
Common uses of watt-hours include: Battery capacity ratings; Small electronics energy use; Solar panel and storage sizing; Portable power station specifications.
What is a joule?
A joule is the SI derived unit of energy, equal to the work done when a force of one newton moves an object one meter (1 N·m). Named after the English physicist James Prescott Joule, who established the mechanical equivalent of heat in the 1840s. The joule became the SI standard for all forms of energy, work, and heat.
Common uses of joules include: Scientific and engineering energy calculations; Nutrition labeling in metric countries; Mechanical work and kinetic energy; Electrical energy in physics (watt-seconds).
Watt-hours to joules worked examples
Here are some common values converted:
1 Wh = 3,600 J 5 Wh = 18,000 J 10 Wh = 36,000 J 50 Wh = 180,000 J 100 Wh = 360,000 J
Frequently asked questions
How many joules are in one watt-hour?
One watt-hour (Wh) equals 3,600 joules (J). Multiply any value in watt-hours by 3,600 to convert to joules.
How do I convert watt-hours to joules?
Multiply the value in watt-hours by 3,600. For example, 5 Wh × 3,600 = 18,000 J.
How do I convert joules to watt-hours?
Multiply the value in joules by 0.000277777778, or divide by 3,600. Use the swap button on the converter above to reverse the direction.
Is the watt-hour to joule conversion exact?
The thermochemical calorie is defined as exactly 4.184 J and the BTU as 1055.056 J. Conversions between SI energy units are exact.
What is the formula for watt-hours to joules?
The formula is: J = Wh × 3,600. This comes from the definition of both units relative to the joule.