Convert Wh to kWh
Convert Wh to kWh instantly. 1 Wh = 0.001 kWh. Formula, worked examples and a quick reference table.
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One watt-hour equals 0.001 kilowatt-hours. To convert any number of watt-hours to kilowatt-hours, multiply by 0.001.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Energy conversions sit between physics and the kitchen. The joule is the SI unit and the one every equation uses; the calorie survives on food labels, where it is actually a kilocalorie a thousand times larger than the physicist’s calorie; and the kilowatt-hour is what an electricity meter counts. All three measure the same quantity, which is why an appliance’s consumption and a meal’s energy content can, in principle, be compared directly.
Wh to kWh formula
To go the other way, use watt-hour = kilowatt-hour ÷ 0.001.
About these units
A watt-hour is one watt sustained for an hour, or 3,600 joules. It is the unit battery capacities are rated in, which makes it directly comparable across devices in a way that milliamp-hours are not.
The kilowatt-hour is the unit electricity is billed in worldwide: one kilowatt drawn for one hour, or 3.6 megajoules.
Watt-hour is also written watt hours. Kilowatt-hour is also written kilowatt hours and units of electricity.
Sources
Wh to kWh conversion table
| Watt-hour | Kilowatt-hour |
|---|---|
| 1 Wh | 0.001 kWh |
| 2 Wh | 0.002 kWh |
| 3 Wh | 0.003 kWh |
| 5 Wh | 0.005 kWh |
| 10 Wh | 0.01 kWh |
| 20 Wh | 0.02 kWh |
| 25 Wh | 0.025 kWh |
| 50 Wh | 0.05 kWh |
| 100 Wh | 0.1 kWh |
| 250 Wh | 0.25 kWh |
| 500 Wh | 0.5 kWh |
| 1,000 Wh | 1 kWh |
Frequently asked questions
How many kilowatt-hours are in a watt-hour? +
There are 0.001 kilowatt-hours in one watt-hour.
What is 10 Wh in kWh? +
10 Wh equals 0.01 kWh. Multiply 10 by 0.001.
How do I convert kilowatt-hour back to watt-hour? +
Use watt-hour = kilowatt-hour ÷ 0.001. The converter above handles both directions, or see our dedicated kWh to Wh page.
How accurate is this watt-hour to kilowatt-hour conversion? +
The factor used is 0.001, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate Wh to kWh in my head? +
Divide by 1,000. That matches the true factor of 0.001 exactly, so no adjustment is needed for a mental estimate.