Convert Horsepower to Watts
1 horsepower is 745.699872 W. One horsepower is exactly 745.699871582 watts.
One horsepower is 745.69987 watts. To convert horsepower to watts, multiply by 745.69987; to go the other way, divide by 745.69987 or multiply by 0.0013410221. The factor is exact rather than rounded: it follows from NIST Special Publication 811. Mechanical horsepower: exactly 550 foot-pounds of work every second, the figure James Watt settled on to sell engines against pit ponies.
Factor checked against the defining standard · How we check
- Horsepower × 745.69987
value * 745.699871582745.7 W
1 horsepower in every power unit
| Unit | Value | Exact factor |
|---|---|---|
| horsepower (as entered) | 1 hp | — |
| metric horsepower | 1.013869665 PS | × 1.01386966542 |
| watts | 745.6998716 W | × 745.699871582 |
| kilowatts | 0.7456998716 kW | × 0.745699871582 |
| megawatts | 0.0007456998716 MW | × 0.000745699871582 |
| BTU per hour | 2,544.433578 BTU/h | × 2,544.43357764 |
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 horsepower to watts?
- 1.Take the measurement in horsepower.
- 2.Multiply by 745.69987 — that is how many watts fit in one horsepower.
- 3.To go back the other way, divide by 745.69987, or multiply by 0.0013410221.
Worked example: 25 horsepower to watts
- Formula
- hp × 745.69987 = W
- Arithmetic
- 25 × 745.69987 = 18,642.49679 W
- Answer
- 25 hp = 18,642.49679 W
The factor is rounded for display; the figure above is computed from the full value.
Horsepower to watts conversion table
| Horsepower | Watts |
|---|---|
| 1 hp | 745.699872 W |
| 2 hp | 1,491.399743 W |
| 3 hp | 2,237.099615 W |
| 4 hp | 2,982.799486 W |
| 5 hp | 3,728.499358 W |
| 6 hp | 4,474.199229 W |
| 7 hp | 5,219.899101 W |
| 8 hp | 5,965.598973 W |
| 9 hp | 6,711.298844 W |
| 10 hp | 7,456.998716 W |
| 12 hp | 8,948.398459 W |
| 15 hp | 11,185.498074 W |
| 20 hp | 14,913.997432 W |
| 25 hp | 18,642.49679 W |
| 50 hp | 37,284.993579 W |
| 100 hp | 74,569.987158 W |
| 200 hp | 149,139.974316 W |
| 300 hp | 223,709.961475 W |
| 500 hp | 372,849.935791 W |
| 1000 hp | 745,699.871582 W |
| 2000 hp | 1,491,399.743164 W |
| 5000 hp | 3,728,499.35791 W |
| 10000 hp | 7,456,998.71582 W |
What is a horsepower?
Mechanical horsepower: exactly 550 foot-pounds of work every second, the figure James Watt settled on to sell engines against pit ponies. US vehicle and motor ratings use it.
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 horsepower?
One horsepower is 745.69987 watts. Going the other way, one watt is 0.0013410221 horsepower. 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
| Unit | Symbol | One of these is |
|---|---|---|
| Horsepower | hp | 745.69987 watt |
| Metric horsepower | PS | 735.49875 watt |
| Watts | W | the base unit |
| Kilowatts | kW | 1000 watt |
| Megawatts | MW | 1000000 watt |
| BTU per hour | BTU/h | 0.29307107 watt |
Source: NIST Special Publication 811 — mechanical horsepower is 550 ft·lbf/s exactly
Questions people actually ask
- How many watts are in a horsepower?
- 745.69987. 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 horsepower?
- Divide by 745.69987, or multiply by 0.0013410221 — they are the same operation.
Other power conversions
Watts to horsepower — the same conversion the other way.