kilowatt-hour

American  

[kil-uh-wot-ouuhr, -ou-er] / ˈkɪl əˌwɒtˈaʊər, -ˈaʊ ər /

noun

1. a unit of energy, equivalent to the energy transferred or expended in one hour by one kilowatt of power; approximately 1.34 horsepower-hours. kWh, K.W.H., kwhr

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kilowatt-hour British  

noun

1.  kWh.  a unit of energy equal to the work done by a power of 1000 watts in one hour

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kilowatt-hour Scientific  

1. A unit used to measure energy, especially electrical energy in commercial applications. One kilowatt-hour is equal to one kilowatt of power produced or consumed over a period of one hour, or 3.6 × 10 ⁶ joules.

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kilowatt-hour Cultural  

1. A unit of energy: the expenditure of one kilowatt of power for one hour. A toaster running for an hour will use about this much energy.

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Etymology

Origin of kilowatt-hour

First recorded in 1890–95

Compare meaning

How does kilowatt-hour compare to similar and commonly confused words? Explore the most common comparisons:

• kilowatt vs. kilowatt-hour

Example Sentences

The average price of electricity in U.S. cities is up to about 19 cents per kilowatt-hour, according to Federal Reserve data.

From Barron's • Feb. 24, 2026

Chinese data centers can now secure power for as little as 3 cents a kilowatt-hour using longer-term purchase agreements, according to China’s National Energy Administration.

From The Wall Street Journal • Dec. 11, 2025

California now has the nation’s second-highest residential electricity prices at 31.9 cents a kilowatt-hour in 2024, almost double the national price of 16.5 cents.

From The Wall Street Journal • Oct. 23, 2025

For all American urban consumers, the price of electricity per kilowatt-hour was 19 cents in August, according to government data — a record high.

From MarketWatch • Oct. 15, 2025

One kilowatt-hour per sol is ... it can be anything . . . um ...

From "The Martian" by Andy Weir