Convert watts to kW
Convert watts to kW instantly. 1 W = 0.001 kW. Formula, worked examples and a quick reference table.
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One watt equals 0.001 kilowatts. To convert any number of watts to kilowatts, 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.
Power is energy per unit time, and the conversions here are all between ways of expressing that rate. Watts and kilowatts are the SI forms; horsepower survives in engine ratings because James Watt coined it to sell steam engines against the animals they replaced. Confusing power with energy is the persistent error in this category: a wattage tells you nothing about consumption or cost until a duration is attached to it.
watts to kW formula
To go the other way, use watt = kilowatt ÷ 0.001.
About these units
The watt is one joule per second — a rate, not a quantity. An appliance’s wattage tells you nothing about its running cost until you say how long it runs.
A kilowatt is 1,000 watts, roughly 1.34 mechanical horsepower. It is the standard rating for electric motors, EV chargers and domestic supply capacity.
Watt is also written watts. Kilowatt is also written kilowatts.
Sources
watts to kW conversion table
| Watt | Kilowatt |
|---|---|
| 1 W | 0.001 kW |
| 2 W | 0.002 kW |
| 3 W | 0.003 kW |
| 5 W | 0.005 kW |
| 10 W | 0.01 kW |
| 20 W | 0.02 kW |
| 25 W | 0.025 kW |
| 50 W | 0.05 kW |
| 100 W | 0.1 kW |
| 250 W | 0.25 kW |
| 500 W | 0.5 kW |
| 1,000 W | 1 kW |
Frequently asked questions
How many kilowatts are in a watt? +
There are 0.001 kilowatts in one watt.
What is 10 W in kW? +
10 W equals 0.01 kW. Multiply 10 by 0.001.
How do I convert kilowatt back to watt? +
Use watt = kilowatt ÷ 0.001. The converter above handles both directions, or see our dedicated kW to watts page.
How accurate is this watt to kilowatt 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 W to kW 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.