How to convert watts to horsepower
Formula: hp = W ÷ 745.7
Worked example: 1,500 W → 1,500 ÷ 745.7 = 2.01153 hp
One mechanical horsepower is 745.7 watts. A 1/2 hp garbage disposal or pump motor therefore produces about 373 W of mechanical power and draws somewhat more from the outlet.
Watts to horsepower conversion chart
| Watts (W) | Horsepower (hp) |
|---|---|
| 1 W | 0.00134102 hp |
| 2 W | 0.00268204 hp |
| 3 W | 0.00402307 hp |
| 4 W | 0.00536409 hp |
| 5 W | 0.00670511 hp |
| 6 W | 0.00804613 hp |
| 7 W | 0.00938715 hp |
| 8 W | 0.0107282 hp |
| 9 W | 0.0120692 hp |
| 10 W | 0.0134102 hp |
| 12 W | 0.0160923 hp |
| 15 W | 0.0201153 hp |
| 20 W | 0.0268204 hp |
| 25 W | 0.0335256 hp |
| 30 W | 0.0402307 hp |
| 40 W | 0.0536409 hp |
| 50 W | 0.0670511 hp |
| 75 W | 0.100577 hp |
| 100 W | 0.134102 hp |
| 250 W | 0.335256 hp |
| 500 W | 0.670511 hp |
| 1,000 W | 1.34102 hp |
What is a watt?
The watt is the SI unit of power: one joule of energy per second. Light bulbs, chargers and small appliances are rated in watts; an LED bulb draws about 9 W and a hair dryer up to 1,800 W.
What is one horsepower?
Mechanical horsepower, defined as 550 foot-pounds per second, equals about 745.7 watts. It is the unit of US and UK car engines, lawn mowers and boat motors. The word stays the same in the plural.