Watts to Horsepower Converter
Convert watts to horsepower and horsepower to watts instantly.
Watts to Horsepower - Quick Reference
| Watts (W) | Horsepower (hp) |
|---|---|
| 100 | 0.134 |
| 500 | 0.670 |
| 745.7 | 1.000 |
| 1000 | 1.341 |
| 5000 | 6.706 |
The Conversion Factor
The watt is the SI unit of power, while horsepower is a traditional unit still widely used to rate engines and motors. This calculator uses mechanical (imperial) horsepower, where one horsepower equals exactly 745.699872 watts. The relationship is:
- 1 hp = 745.7 W (multiply horsepower by 745.699872)
- 1 W = 0.00134102 hp (divide watts by 745.699872)
- 1 kW = 1.34102 hp (a useful shortcut for larger values)
Mechanical vs. Metric Horsepower
There is more than one definition of horsepower, so it is important to know which one you are using:
- Mechanical (imperial) horsepower: 1 hp = 745.699872 W. This is the unit used in the United States and the UK and is the one applied by this converter.
- Metric horsepower (PS / CV): 1 PS = 735.49875 W. Common in European automotive specifications. It is roughly 1.4% smaller than mechanical horsepower, so the two are not interchangeable.
Common Uses
Engines
Car, motorcycle, and small-engine power ratings are usually expressed in horsepower, while electrical output is given in watts or kilowatts.
Electric Motors
Pumps, fans, and industrial motors are often rated in watts or kilowatts; converting to horsepower helps compare them with mechanical equipment.
Appliances
Power tools and household appliances list wattage on their nameplates, making conversion useful when comparing performance across products.