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

Its current energy rate is 8.5-cents per kilowatt-hour, which rises to around 14.3 to 14.5 cents after adding utility transmission-and-distribution costs.

From The Wall Street Journal • Feb. 4, 2026

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

According to a December BloombergNEF study, prices for lithium-ion battery packs dropped 20% in 2024, reaching $115 per kilowatt-hour.

From MarketWatch • Oct. 18, 2025

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

From "The Martian" by Andy Weir