Milliwatt (mW)
One thousandth of a watt.
What is a milliwatt?
- Symbol
- mW
- Quantity
- Power
- Unit system
- SI
- Definition
- One thousandth of a watt.
- Exact
- Yes, the value is exact by definition
- Source
- SI Brochure, 9th edition (BIPM, 2019)
Common applications
Used for laser pointers, radio transmitters and the power draw of small electronics.
Milliwatt in other power units
- 1 mW = 0.001 WWatt
- 1 mW = 0.000001 kWKilowatt
- 1 mW = 1e-9 MWMegawatt
- 1 mW = 1e-12 GWGigawatt
- 1 mW ≈ 0.00000134102209 hpHorsepower (mechanical)
- 1 mW ≈ 0.000001359621617 PSHorsepower (metric)
- 1 mW ≈ 0.003412141633 BTU/hBTU (IT) per hour
- 1 mW ≈ 0.0007375621493 ft·lbf/sFoot-pound-force per second
Milliwatt quick reference
| Milliwatt | Kilowatt | Horsepower (mechanical) | Watt |
|---|---|---|---|
| 1 mW | = 0.000001 kW | ≈ 0.00000134102209 hp | = 0.001 W |
| 10 mW | = 0.00001 kW | ≈ 0.0000134102209 hp | = 0.01 W |
| 100 mW | = 0.0001 kW | ≈ 0.000134102209 hp | = 0.1 W |
| 1000 mW | = 0.001 kW | ≈ 0.00134102209 hp | = 1 W |
Where the milliwatt fits
The next larger power unit is the BTU per hour (BTU/h). 1 mW ≈ 0.003412141633 BTU/h, and 1 BTU/h ≈ 293.0710702 mW.
Frequently asked questions
- How many kilowatts are in one milliwatt?
- One milliwatt = 0.000001 kW (kilowatts).
- How many horsepower are in one milliwatt?
- One milliwatt ≈ 0.00000134102209 hp (horsepower).
- How many watts are in one milliwatt?
- One milliwatt = 0.001 W (watts).