Watts to Kilowatts
Type a value in either box to convert between watts and kilowatts. The factor is 0.001.
| Watts | Kilowatts |
|---|---|
| 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 |
| 25 W | 0.025 kW |
| 50 W | 0.05 kW |
| 100 W | 0.1 kW |
How to use
- Enter a value in the Watts field.
- The Kilowatts figure appears immediately — no button to press.
- Typing in the Kilowatts field converts back to Watts the same way.
- Use the reference table for the values that come up most often.
Watts to Kilowatts formula
To convert watts to kilowatts, multiply by 0.001.
kW = W × 0.001
Put another way, one watt is exactly 1/1,000 of a kilowatt.
Why this factor: the watt and the kilowatt are both defined against the watt, so dividing one definition by the other gives 0.001 directly. Both definitions are set out in full below.
To go the other way, divide by 0.001 — or use the Kilowatts to Watts converter, which is the same calculation reversed.
Worked example
Take 500 W and multiply by the factor 0.001: the result is 0.5 kW.
500 W × 0.001 = 0.5 kW
The converter above does this for any value you type, in either direction.
What is a watt?
The watt is the SI unit of power — the rate of one joule of energy per second.
Definition: Defined as 1 J/s. Named after James Watt.
Where it is used: Appliance and light-bulb ratings, audio output, and all scientific power calculations.
What is a kilowatt?
A kilowatt is 1,000 watts, the practical unit for substantial electrical loads.
Definition: Exactly 1,000 watts.
Where it is used: Electric motor and vehicle output, heating systems, EV charger ratings, and solar array capacity.
Watts vs Kilowatts
The watt is an SI unit while the kilowatt is a metric unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many kilowatts are in a watt?
One watt equals 0.001 kilowatts.
What is the formula to convert watts to kilowatts?
Multiply the number of watts by 0.001. To reverse it, divide by 0.001 instead.
How do I convert kilowatts back to watts?
Divide by 0.001, which is the same as multiplying by 1000.
How many kilowatts are in 10 watts?
10 W works out to 0.01 kW.
How is the watt defined?
Defined as 1 J/s. Named after James Watt.