Watt | Power, Energy, Electricity | Britannica (original) (raw)

_verified_Cite

While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.

Select Citation Style

Feedback

Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).

Feedback Type

Your Feedback

Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Also known as: W

Written and fact-checked by

The Editors of Encyclopaedia Britannica

watt, unit of power in the International System of Units (SI) equal to one joule of work performed per second, or to 1/746 horsepower. An equivalent is the power dissipated in an electrical conductor carrying one ampere current between points at one volt potential difference. It is named in honour of James Watt, British engineer and inventor. One thousand watts equal one kilowatt. Most electrical devices are rated in watts.