Milliwatts Converter
Convert Milliwatts (mW) to any other power unit. The table below gives the exact figure for each unit, and every conversion is worked from the same engine as the converter.
What milliwatts convert to
One mW in every other power unit.
| Unit | 1 mW | Reverse |
|---|---|---|
| Watts | 0.001 W | 1,000 mW |
| Kilowatts | 1e-6 kW | 1,000,000 mW |
| Megawatts | 1e-9 MW | 1,000,000,000 mW |
| Horsepower (mechanical) | 1.341e-6 hp | 745,699.871582 mW |
| Metric horsepower | 1.3596e-6 PS | 735,498.75 mW |
| BTU per hour | 0.003412 BTU/h | 293.07107 mW |
Multiply a milliwatts figure by the figure in the second column to get the unit in the first, or multiply by the third column to go the other way.
Milliwatts conversion reference
Milliwatts to Watts
One milliwatts is 0.001 watts, and one watts is 1,000 milliwatts.
The watt is the SI unit of power: one joule per second. It is used for light bulbs, small appliances and solar panel ratings; an LED bulb is typically 5 to 15 watts.
- 1 mW= 0.001 W
- 5 mW= 0.005 W
- 10 mW= 0.01 W
The watt is the SI unit of power: one joule of energy transferred each second. Its symbol is W, and it is the base from which every larger power unit is built.
Watt ratings appear on light bulbs, televisions, kettles, solar panels, inverters and small generators. Physics and engineering use the watt for every rate of energy transfer, from a laser to a motor.
Milliwatts to Kilowatts
One milliwatts is 1e-6 kilowatts, and one kilowatts is 1,000,000 milliwatts.
A kilowatt is 1,000 watts. It is the usual unit for appliance ratings, generators, inverters and household electricity demand.
- 1 mW= 1e-6 kW
- 5 mW= 5e-6 kW
- 10 mW= 1e-5 kW
Exactly 1,000 watts make one kilowatt, written kW. This is the multiple that electrical equipment ratings use, and it equals one thousand joules of energy transferred per second.
Domestic appliance labels, generator sets, inverters, solar arrays and electric motors are all rated in kilowatts. Household demand and the capacity of a standby generator are usually quoted this way.
Milliwatts to Megawatts
One milliwatts is 1e-9 megawatts, and one megawatts is 1,000,000,000 milliwatts.
A megawatt is 1,000 kilowatts. It is used for power stations, industrial loads and grid capacity, where large generator sets run into the megawatts.
- 1 mW= 1e-9 MW
- 5 mW= 5e-9 MW
- 10 mW= 1e-8 MW
A megawatt is 1,000 kilowatts, or one million watts, and it carries the symbol MW. Power at this scale is quoted in megawatts because a figure in kilowatts would run to several digits.
Grid-scale generating stations, industrial plants, large data centres and utility-scale solar farms are described in megawatts of capacity. Transmission and distribution planning also uses the unit for load forecasts.
Milliwatts to Horsepower (mechanical)
One milliwatts is 1.341e-6 horsepower (mechanical), and one horsepower (mechanical) is 745,699.871582 milliwatts.
Mechanical horsepower is 745.7 watts, the unit used for engine and motor output in the United States and UK. It is a different size from metric horsepower.
- 100 mW= 1.341e-4 hp
- 500 mW= 6.7051e-4 hp
- 1,000 mW= 0.001341 hp
Mechanical horsepower is exactly 745.7 watts, and metric horsepower is exactly 735.49875 watts. The two definitions differ by about 1.4 percent, so a figure carries a larger number in mechanical horsepower.
Vehicle engine output, pump and compressor motors, and agricultural machinery are commonly rated in horsepower. Metric horsepower is used for engine figures in much of Europe and Asia, while mechanical horsepower dominates in the United States.
Milliwatts to Metric horsepower
One milliwatts is 1.3596e-6 metric horsepower, and one metric horsepower is 735,498.75 milliwatts.
Metric horsepower (PS) is 735.49875 watts, used for vehicle engine ratings across much of Europe and Asia. It is slightly smaller than mechanical horsepower.
- 100 mW= 1.3596e-4 PS
- 500 mW= 6.7981e-4 PS
- 1,000 mW= 0.00136 PS
Milliwatts to BTU per hour
One milliwatts is 0.003412 btu per hour, and one btu per hour is 293.07107 milliwatts.
One BTU per hour is 0.29307107 watts. It is used for air-conditioning and heating capacity, where '12,000 BTU' means roughly 3.5 kW.
- 1 mW= 0.003412 BTU/h
- 5 mW= 0.017061 BTU/h
- 10 mW= 0.034121 BTU/h
One BTU per hour is exactly 0.29307107017222 watts, because one BTU is exactly 1,055.05585262 joules and an hour holds 3,600 seconds. The symbol is BTU/h.
Air conditioners, heat pumps, furnaces and chillers are rated in BTU per hour, and the figure on a room air conditioner describes its cooling capacity. Heating and cooling engineering uses the same unit for equipment sizing.
What milliwatts are used for
A milliwatt is one thousandth of a watt. It is used for small electronics, radio transmission power and laser pointers; an indicator LED draws a few milliwatts.
Metric power conversions are exact. Check whether a horsepower figure is mechanical or metric before comparing two engines.
Within the metric units a power conversion is a power of a thousand: watts to kilowatts, kilowatts to megawatts, and back. Those pairs are decimal shifts and a reader can do them without a converter.
Anything involving horsepower is a multiplication by a definition rather than a shift, and there are two definitions. Mechanical horsepower is exactly 745.7 watts and metric horsepower exactly 735.49875 watts, so the same engine carries a larger figure in mechanical horsepower than in metric.
When checking a power conversion, convert to watts first, because every unit in this dimension is defined against the watt and the intermediate value makes the comparison obvious. The trap is comparing a horsepower figure with a kilowatt figure without establishing which horsepower was quoted.
Tanzania reference points
Real quantities, converted into milliwatts.
Tanzania's installed electricity generation capacity
2,881.332 MW = 2,881,332,000,000 mW
EWURA reports 2,842.96 MW on the main grid and 38.372 MW off-grid, with TANESCO holding 92.31% of it. Installed capacity is what the country could generate at once, not what it generates on an average day.
Source: EWURA Fact Sheet — electricity sub-sector (installed capacity) · verified 2026-09-14
Milliwatts conversion tables
Milliwatts to Watts
| Milliwatts (mW) | Watts (W) |
|---|---|
| 1 | 0.001 |
| 2 | 0.002 |
| 3 | 0.003 |
| 4 | 0.004 |
| 5 | 0.005 |
| 10 | 0.01 |
| 25 | 0.025 |
| 50 | 0.05 |
| 100 | 0.1 |
Milliwatts to Kilowatts
| Milliwatts (mW) | Kilowatts (kW) |
|---|---|
| 1 | 1e-6 |
| 2 | 2e-6 |
| 3 | 3e-6 |
| 4 | 4e-6 |
| 5 | 5e-6 |
| 10 | 1e-5 |
| 25 | 2.5e-5 |
| 50 | 5e-5 |
| 100 | 1e-4 |
Milliwatts to Megawatts
| Milliwatts (mW) | Megawatts (MW) |
|---|---|
| 1 | 1e-9 |
| 2 | 2e-9 |
| 3 | 3e-9 |
| 4 | 4e-9 |
| 5 | 5e-9 |
| 10 | 1e-8 |
| 25 | 2.5e-8 |
| 50 | 5e-8 |
| 100 | 1e-7 |
Related calculators
Try these calculators that use power measurements.