How to convert watts to horsepower
- Take the value in watts.
- Use the formula horsepower = watts × 0.00134102209.
- For example, 100 W is 0.134 hp.
About watts and horsepower
One mechanical horsepower is 745.7 watts, so divide watts by 745.7 to get horsepower. A rough rule is that 750 W is about 1 hp.
Motors on e-bikes, pumps, drills and power tools are rated in watts, while older tools, compressors and US specs often give horsepower. E-bike rules in the EU and US both set their limits in watts.
Examples
- 100 W (a classic incandescent light bulb) is 0.134 hp
- 250 W (the EU limit for an e-bike motor’s rated power) is 0.335 hp
- 750 W (the US limit for a low-speed electric bicycle) is 1.01 hp
- 1,500 W (a typical US space heater on high) is 2.01 hp
Watts to horsepower chart
| Watts (W) | Horsepower (hp) |
|---|---|
| 1 | 0.00134 |
| 10 | 0.0134 |
| 50 | 0.0671 |
| 100 | 0.134 |
| 200 | 0.268 |
| 250 | 0.335 |
| 300 | 0.402 |
| 500 | 0.671 |
| 745.7 | 1 |
| Watts (W) | Horsepower (hp) |
|---|---|
| 750 | 1.01 |
| 1,000 | 1.34 |
| 1,500 | 2.01 |
| 2,000 | 2.68 |
| 3,000 | 4.02 |
| 5,000 | 6.71 |
| 7,500 | 10.06 |
| 10,000 | 13.41 |