Conversions

kW to kWh Calculator

By HowMuchWatts Editorial Team Reviewed June 30, 2026 Formula and source method

Power (kW) is the rate of use; energy (kWh) is power used over time. This calculator converts a kW rating and run time into kWh, plus its cost.

Change any number below — your result updates instantly, no button to click.

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Results

Energy used

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Cost

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Written & maintained by the HowMuchWatts team · Last updated June 30, 2026 · How we verify our numbers

How it works

Energy (kWh) = power (kW) × time (hours). Cost = energy × rate. For watts instead of kilowatts, divide watts by 1000 first (e.g. 1500 W = 1.5 kW).

Frequently asked questions

What’s the difference between kW and kWh?

kW is power — how fast energy is used. kWh is energy — how much is used over time. A 2 kW heater running 3 hours uses 6 kWh.

How do I convert watts to kW?

Divide by 1000. 500 W = 0.5 kW, 1500 W = 1.5 kW.

Why does my bill use kWh?

You are billed for total energy consumed, which is measured in kWh, not for the instantaneous power (kW).

These calculators provide general estimates for educational purposes only and are not financial advice. Real-world results depend on factors not captured here. Verify figures independently before making any purchase or financial decision.

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