Convert Watts to Horsepower
1 watt is 0.001341 hp. One watt is exactly 0.0013410220896 horsepower.
One watt is 0.0013410221 horsepower. To convert watts to horsepower, multiply by 0.0013410221; to go the other way, divide by 0.0013410221 or multiply by 745.69987. The factor is exact rather than rounded: it follows from NIST Special Publication 811. The SI unit: one joule every second.
Factor checked against the defining standard · How we check
- Watts × 0.0013410221
value * 0.00134102208960.001 hp
1 watt in every power unit
| Unit | Value | Exact factor |
|---|---|---|
| horsepower | 0.00134102209 hp | × 0.0013410220896 |
| metric horsepower | 0.001359621617 PS | × 0.0013596216173 |
| watts (as entered) | 1 W | — |
| kilowatts | 0.001 kW | × 0.001 |
| megawatts | 0.000001 MW | × 0.000001 |
| BTU per hour | 3.412141633 BTU/h | × 3.41214163313 |
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 watts to horsepower?
- 1.Take the measurement in watts.
- 2.Multiply by 0.0013410221 — that is how many horsepower fit in one watt.
- 3.To go back the other way, divide by 0.0013410221, or multiply by 745.69987.
Worked example: 25 watts to horsepower
- Formula
- W × 0.0013410221 = hp
- Arithmetic
- 25 × 0.0013410221 = 0.033526 hp
- Answer
- 25 W = 0.033526 hp
The factor is rounded for display; the figure above is computed from the full value.
Watts to horsepower conversion table
| Watts | Horsepower |
|---|---|
| 1 W | 0.001341 hp |
| 2 W | 0.002682 hp |
| 3 W | 0.004023 hp |
| 4 W | 0.005364 hp |
| 5 W | 0.006705 hp |
| 6 W | 0.008046 hp |
| 7 W | 0.009387 hp |
| 8 W | 0.010728 hp |
| 9 W | 0.012069 hp |
| 10 W | 0.01341 hp |
| 12 W | 0.016092 hp |
| 15 W | 0.020115 hp |
| 20 W | 0.02682 hp |
| 25 W | 0.033526 hp |
| 50 W | 0.067051 hp |
| 100 W | 0.134102 hp |
| 200 W | 0.268204 hp |
| 300 W | 0.402307 hp |
| 500 W | 0.670511 hp |
| 1000 W | 1.341022 hp |
| 2000 W | 2.682044 hp |
| 5000 W | 6.70511 hp |
| 10000 W | 13.410221 hp |
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.
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.
How many horsepower are in a watt?
One watt is 0.0013410221 horsepower. Going the other way, one horsepower is 745.69987 watts. 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 horsepower are in a watt?
- 0.0013410221. 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.
- How do I convert horsepower back to watts?
- Divide by 0.0013410221, or multiply by 745.69987 — they are the same operation.
Other power conversions
Horsepower to watts — the same conversion the other way.