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kWh to Wh Calculator

Kilowatt-hours and watt-hours are both units of energy. Enter any value in kWh to convert it directly to Wh; no time period is needed.

Quick answerMultiply kWh by 1,000 to get Wh. Exactly 1 kWh = 1,000 Wh, 0.1 kWh = 100 Wh, and 2.5 kWh = 2,500 Wh. This converts energy to energy; converting kWh to watts also requires a time period.

Do you need watt-hours or watts?

These similar-looking conversions answer different questions. Choose the result you actually need.

Current calculator Energy in watt-hours (Wh) Use this for the fixed energy conversion: kWh × 1,000. No time value is needed.
Switch calculator Average power in watts (W) Use this when you know kWh and the time period. Hours are required.

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Written & maintained by the HowMuchWatts team · Last updated August 18, 2026 · How we verify our numbers

How it works

Watt-hours = kilowatt-hours × 1,000. The conversion is exact because the prefix kilo means 1,000: 1 kWh = 1,000 Wh, so 2.5 kWh = 2,500 Wh.

kWh to Wh conversion table

Multiply any kilowatt-hour value by 1,000 to get watt-hours. These common values are exact.

Kilowatt-hoursWatt-hours
0.001 kWh1 Wh
0.01 kWh10 Wh
0.1 kWh100 Wh
0.5 kWh500 Wh
1 kWh1,000 Wh
2 kWh2,000 Wh
2.5 kWh2,500 Wh
5 kWh5,000 Wh
10 kWh10,000 Wh
50 kWh50,000 Wh
100 kWh100,000 Wh

To convert in the opposite direction, divide watt-hours by 1,000 or use the linked Wh to kWh calculator.

Worked example: convert 2.5 kWh to Wh

Multiply 2.5 by 1,000. The result is 2,500 Wh. Both numbers describe the same amount of energy; only the scale and unit label change.

When watt-hours are more useful than kilowatt-hours

Electricity bills and large home batteries usually use kWh because the numbers stay compact. Portable power stations, small batteries and device energy use are often shown in Wh. Converting to the same unit makes capacities easier to compare.

This conversion does not produce watts. Watts measure power, while Wh and kWh measure energy. To find average watts from kWh, you also need the number of hours over which the energy was used.

Why the 1,000-to-1 conversion is exact

The hour part does not change when converting kWh to Wh; only the metric prefix changes. The International Bureau of Weights and Measures (BIPM) defines kilo as 10³, or 1,000. NIST lists 1 Wh as 3.6 × 10³ joules and 1 kWh as 3.6 × 10⁶ joules—the same exact 1,000-to-1 ratio. No estimated efficiency or rounding factor is involved.

Sources used for assumptions: BIPM — SI Brochure, 9th edition: kilo is 10³; NIST — Guide to the SI, Appendix B.9: Wh and kWh energy factors.

Frequently asked questions

How many watt-hours are in 1 kWh?

Exactly 1,000 Wh. Multiply any kWh value by 1,000 to convert it to watt-hours.

How many watt-hours are in 5 kWh?

5 kWh equals 5,000 Wh because 5 × 1,000 = 5,000.

Is kWh to Wh the same as kWh to watts?

No. kWh and Wh are both energy units, so the conversion is a fixed factor of 1,000. Converting kWh to average watts also requires a time period.

How do I convert Wh back to kWh?

Divide the watt-hours by 1,000. For example, 2,500 Wh ÷ 1,000 = 2.5 kWh.

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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