Horsepower (mechanical) to Milliwatts Converter
Convert Horsepower (mechanical) (hp) to Milliwatts (mW) instantly, or use the conversion table below to look up common values.
Horsepower (mechanical) to Milliwatts conversion table
| Horsepower (mechanical) (hp) | Milliwatts (mW) |
|---|---|
| 1 | 745,699.871582 |
| 2 | 1,491,399.743165 |
| 3 | 2,237,099.614747 |
| 4 | 2,982,799.486329 |
| 5 | 3,728,499.357911 |
| 10 | 7,456,998.715823 |
| 25 | 18,642,496.789557 |
| 50 | 37,284,993.579114 |
| 100 | 74,569,987.158227 |
How to convert Horsepower (mechanical) to Milliwatts
1 hp equals 745,699.871582 mW. Use the converter above for any value, or read the table for common conversions.
mW = hp × 745699.8715822703 · hp = mW × 0.0000013410220895950279Multiply a horsepower (mechanical) figure by 745,699.871582 to get milliwatts, or divide it by 1.341e-6 to go the other way.
Worked examples
- 1 hp= 745,699.871582 mW
- 5 hp= 3,728,499.357911 mW
- 10 hp= 7,456,998.715823 mW
- 100 hp= 74,569,987.158227 mW
- 500 hp= 372,849,935.791135 mW
What these units are
Horsepower (mechanical) (hp). 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.
Milliwatts (mW). 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.
Converting Horsepower (mechanical) to Milliwatts in practice
Working in horsepower (mechanical)
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.
Power is a rate, so multiplying horsepower by a running time gives an energy amount in joules or watt-hours. The gap of about 1.4 percent between the two horsepower definitions is carried through every conversion to watts.
Comparing two engine ratings without knowing which horsepower definition applies is the usual error, and the numbers are not interchangeable. The definition behind a figure should always be established before it is converted.
Horsepower is the unit for engine output, while kilowatts fit appliances, generators and inverters, and BTU per hour fits heating and cooling equipment. Metric horsepower is a separate sibling, so a PS figure and an hp figure differ even when they describe the same engine.
Checking a horsepower (mechanical) to milliwatts conversion
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 the units on this page.
Tanzania's installed electricity generation capacity
2,881.332 MW = 3,863,929.859457 hp = 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
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