Horsepower (mechanical) Converter
Convert Horsepower (mechanical) (hp) 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 horsepower (mechanical) convert to
One hp in every other power unit.
| Unit | 1 hp | Reverse |
|---|---|---|
| Milliwatts | 745,699.871582 mW | 1.341e-6 hp |
| Watts | 745.699872 W | 0.001341 hp |
| Kilowatts | 0.7457 kW | 1.341022 hp |
| Megawatts | 7.457e-4 MW | 1,341.02209 hp |
| Metric horsepower | 1.01387 PS | 0.98632 hp |
| BTU per hour | 2,544.433579 BTU/h | 3.9301e-4 hp |
Multiply a horsepower (mechanical) 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.
Horsepower (mechanical) conversion reference
Horsepower (mechanical) to Milliwatts
One horsepower (mechanical) is 745,699.871582 milliwatts, and one milliwatts is 1.341e-6 horsepower (mechanical).
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.
- 1 hp= 745,699.871582 mW
- 5 hp= 3,728,499.357911 mW
- 10 hp= 7,456,998.715823 mW
Horsepower (mechanical) to Watts
One horsepower (mechanical) is 745.699872 watts, and one watts is 0.001341 horsepower (mechanical).
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 hp= 745.699872 W
- 5 hp= 3,728.499358 W
- 10 hp= 7,456.998716 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.
Horsepower (mechanical) to Kilowatts
One horsepower (mechanical) is 0.7457 kilowatts, and one kilowatts is 1.341022 horsepower (mechanical).
A kilowatt is 1,000 watts. It is the usual unit for appliance ratings, generators, inverters and household electricity demand.
- 1 hp= 0.7457 kW
- 5 hp= 3.728499 kW
- 10 hp= 7.456999 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.
Horsepower (mechanical) to Megawatts
One horsepower (mechanical) is 7.457e-4 megawatts, and one megawatts is 1,341.02209 horsepower (mechanical).
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 hp= 7.457e-4 MW
- 5 hp= 0.003728 MW
- 10 hp= 0.007457 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.
Horsepower (mechanical) to Metric horsepower
One horsepower (mechanical) is 1.01387 metric horsepower, and one metric horsepower is 0.98632 horsepower (mechanical).
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.
- 1 hp= 1.01387 PS
- 5 hp= 5.069348 PS
- 10 hp= 10.138697 PS
Open the Horsepower (mechanical) to Metric horsepower converter
Horsepower (mechanical) to BTU per hour
One horsepower (mechanical) is 2,544.433579 btu per hour, and one btu per hour is 3.9301e-4 horsepower (mechanical).
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 hp= 2,544.433579 BTU/h
- 5 hp= 12,722.167896 BTU/h
- 10 hp= 25,444.335791 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 horsepower (mechanical) are used for
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.
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.
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 horsepower (mechanical).
Tanzania's installed electricity generation capacity
2,881.332 MW = 3,863,929.859457 hp
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
Horsepower (mechanical) conversion tables
Horsepower (mechanical) to Milliwatts
| 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 |
Horsepower (mechanical) to Watts
| Horsepower (mechanical) (hp) | Watts (W) |
|---|---|
| 1 | 745.699872 |
| 2 | 1,491.399743 |
| 3 | 2,237.099615 |
| 4 | 2,982.799486 |
| 5 | 3,728.499358 |
| 10 | 7,456.998716 |
| 25 | 18,642.49679 |
| 50 | 37,284.993579 |
| 100 | 74,569.987158 |
Horsepower (mechanical) to Kilowatts
| Horsepower (mechanical) (hp) | Kilowatts (kW) |
|---|---|
| 1 | 0.7457 |
| 2 | 1.4914 |
| 3 | 2.2371 |
| 4 | 2.982799 |
| 5 | 3.728499 |
| 10 | 7.456999 |
| 25 | 18.642497 |
| 50 | 37.284994 |
| 100 | 74.569987 |
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