W to mW converter (W to mW)
Convert W (W) to mW (mW) with this free calculator. Type a value, press Convert, and the page applies the same factor shown in the formula below — no rounded shortcut, and nothing is stored on a server.
How to convert Watts to mW
1 watt (W) is equal to 1000 milliwatts (mW).
P(mW) = P(W) × 1000
Multiply the power in W by 1000:
Example: Convert 5 W to mW:
P(mW) = 5 × 1000 = 5000 mW
What is a W?
The W (W) is the starting or target unit on this page. Use the calculator above to convert values without looking up the factor by hand.
What is a mW?
The mW (mW) is the starting or target unit on this page. Use the calculator above to convert values without looking up the factor by hand.
This page converts power from W into mW. One W equals 1000 mW.
W to mW conversion table
Common W values and the matching mW result, calculated with the same factor as the widget. Highlight a nearby row if you want a quick check without entering a number.
| W (W) | mW (mW) |
|---|---|
| 0.001 W | 1 mW |
| 0.01 W | 10 mW |
| 0.1 W | 100 mW |
| 1 W | 1000 mW |
| 2 W | 2000 mW |
| 5 W | 5000 mW |
| 10 W | 10000 mW |
| 100 W | 100000 mW |
| 1000 W | 1000000 mW |
How this calculator works
The form on this page is a W-to-mW converter. After you enter a number, JavaScript multiplies or rearranges it with the published conversion factor and writes the mW result in the output box. The step-by-step panel repeats the arithmetic so you can copy it into homework or a spreadsheet.
Reviewed by Hamsen, founder of GigaTables and a biology engineer. See the about page for how formulas are checked before a tool is published.
FAQ
How many mW are in 1 W?
1 W = 1000 mW.
How do I convert W to mW?
Multiply the power in W by 1000:
Is this W to mW converter free?
Yes. GigaTables calculators are free to use in a browser. You do not need an account, and the values you type are not uploaded.