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kW to Milliwatts Converter

Convert kilowatt to milliwatt instantly. 1 kW = 1000000 mW, worked steps and a full reference table.

Formula
mW = kW × 1000000

How to use it

  • Type the value in kilowatt — the result updates as you type.
  • Use Swap to flip the direction, or change either dropdown to convert between any two units.
  • Click the result to copy it. The URL updates too, so you can bookmark or share the exact conversion.

Examples

1 kW1000000 mW
5 kW5000000 mW
10 kW10000000 mW
100 kW100000000 mW

One kilowatt equals 1000000 milliwatts (mW). To convert kilowatts to milliwatts, multiply by 1000000; to go back the other way, multiply by 1.0000e-6 instead.

The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.

What kilowatts and milliwatts actually measure

Kilowatt (kW) — A kilowatt is a thousand watts. Heaters, EV chargers, motors and domestic electricity supply.

Milliwatt (mW) — A milliwatt is a thousandth of a watt. Laser pointers, radio transmit power and low-power electronics.

kW to Milliwatts conversion table

The most common values, worked out in advance. Anything not listed can be typed straight into the converter.

kWmW
1 kW1000000 mW
2 kW2000000 mW
5 kW5000000 mW
10 kW10000000 mW
25 kW25000000 mW
50 kW50000000 mW
100 kW100000000 mW

How to convert kilowatts to milliwatts by hand

Multiply the number of kilowatts by 1000000.

For example, 25 kW × 1000000 = 25000000 mW.

Going the other way, divide by 1000000 — or multiply by 1.0000e-6, which is the same thing and easier to do in your head.

Everything runs in your browser

There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.

Questions people ask

How many mW are in 1 kW?

1 kW equals exactly 1000000 mW. Multiply any value in kilowatt by 1000000 to get milliwatt.

Is anything uploaded to a server?

No. The whole calculation happens in your browser. Nothing is sent anywhere, and the page keeps working offline once loaded.

Runs entirely in your browser. Nothing you type is uploaded, logged or shared.

Last updated 18 August 2026