Convert Milliwatts to Watts
1 milliwatt is 0.001 W. One milliwatt is exactly 0.001 watts.
One milliwatt is 0.001 watts. To convert milliwatts to watts, multiply by 0.001; to go the other way, divide by 0.001 or multiply by 1000. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A thousandth of a watt.
Factor checked against the defining standard · How we check
- Milliwatts × 0.001
1 * 0.0010.001 W
1 milliwatt in every power unit
| Unit | Value | Exact factor |
|---|---|---|
| horsepower | 0.00000134102209 hp | × 0.0000013410220896 |
| metric horsepower | 0.000001359621617 PS | × 0.0000013596216173 |
| watts | 0.001 W | × 0.001 |
| kilowatts | 0.000001 kW | × 0.000001 |
| milliwatts (as entered) | 1 mW | — |
| megawatts | 0.000000001 MW | × 0.000000001 |
| tons of refrigeration | 0.0000002843451361 TR | × 0.000000284345136094 |
| BTU per hour | 0.003412141633 BTU/h | × 0.00341214163313 |
Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert milliwatts to watts? The converter and the working
- 1.Take the measurement in milliwatts.
- 2.Multiply by 0.001 — that is how many watts fit in one milliwatt.
- 3.To go back the other way, divide by 0.001, or multiply by 1000.
Worked example: 25 milliwatts to watts
- Formula
- mW × 0.001 = W
- Arithmetic
- 25 × 0.001 = 0.03 W
- Answer
- 25 mW = 0.03 W
The factor is exact, so this figure is exact too — only the display is rounded.
Milliwatts to watts conversion table
| Milliwatts | Watts |
|---|---|
| 1 mW | 0.001 W |
| 2 mW | 0.002 W |
| 3 mW | 0.003 W |
| 4 mW | 0.004 W |
| 5 mW | 0.01 W |
| 6 mW | 0.01 W |
| 7 mW | 0.01 W |
| 8 mW | 0.01 W |
| 9 mW | 0.01 W |
| 10 mW | 0.01 W |
| 12 mW | 0.01 W |
| 15 mW | 0.02 W |
| 20 mW | 0.02 W |
| 25 mW | 0.03 W |
| 50 mW | 0.05 W |
| 100 mW | 0.1 W |
| 200 mW | 0.2 W |
| 300 mW | 0.3 W |
| 500 mW | 0.5 W |
| 1000 mW | 1 W |
| 2000 mW | 2 W |
| 5000 mW | 5 W |
| 10000 mW | 10 W |
What is a milliwatt?
A thousandth of a watt. Radio transmit power, laser output and audio signal levels are all quoted in it, and dBm is referenced to exactly one.
What is a watt?
The SI unit: one joule every second. A watt is a rate, not an amount, which is the distinction between it and the watt-hour on your electricity bill.
How many watts are in a milliwatt?
One milliwatt is 0.001 watts, exactly. Going the other way, one watt is 1000 milliwatts. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every power unit here
The whole group — 8 units with their symbols and the size of each one in watts — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a milliwatt.
Source: NIST Special Publication 811 — mechanical horsepower is 550 ft·lbf/s exactly
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Questions people actually ask
- How many watts are in a milliwatt?
- 0.001. The SI unit: one joule every second. A watt is a rate, not an amount, which is the distinction between it and the watt-hour on your electricity bill.
- How do I convert watts back to milliwatts?
- Divide by 0.001, or multiply by 1000 — they are the same operation.
Other power conversions
Watts to milliwatts — the same conversion the other way.