Watts to Horsepower Calculator
Convert watts and kilowatts to horsepower instantly, mechanical and electrical.
Convert power in watts (or kilowatts) to horsepower. Useful for electric motors, power tools, and any device rated in watts that you want to compare in HP.
Watts to HP Formula
How to Use This Calculator
- Enter the power in watts.
- Read the horsepower result, with kilowatts shown too.
Worked Example
Three Definitions of Horsepower
The watt-to-HP factor depends on which horsepower you mean. Mechanical HP = 745.7 W (the automotive standard). Electrical HP = exactly 746 W, used for motor ratings. Metric HP (PS) = 735.5 W, common in Europe. For most purposes the mechanical figure is correct, but motor nameplates often use the electrical definition — the 0.3 W difference is negligible for everyday conversions.
Common Uses for Watts-to-HP
This conversion is handy any time a device is rated in watts but you think in horsepower: electric motors, power tools, e-bike and EV drivetrains, generators, and appliances. A 1,500 W angle grinder is about 2 HP; a 3,000 W e-bike motor is roughly 4 HP. It's also the bridge between electrical power draw and mechanical output once you account for motor efficiency.
Watts to HP Conversion Table
| Watts | Mechanical HP | Kilowatts |
|---|---|---|
| 746 | 1.00 | 0.75 |
| 1,500 | 2.01 | 1.5 |
| 3,000 | 4.02 | 3.0 |
| 5,500 | 7.38 | 5.5 |
| 10,000 | 13.41 | 10.0 |
Common Watts to HP Lookups
| Watts | Mechanical HP | Typical use |
|---|---|---|
| 500 | 0.67 | E-bike motor |
| 746 | 1.00 | The definition (electrical HP) |
| 1,000 | 1.34 | Small power tools |
| 1,500 | 2.01 | Household circuit max |
| 3,000 | 4.02 | Large workshop motor |
| 5,000 | 6.71 | EV onboard charger |
| 7,457 | 10.0 | Ten horsepower exactly |
Frequently Asked Questions
One mechanical horsepower equals 745.7 watts. Electrical horsepower is 746 watts and metric horsepower (PS) is 735.5 watts.
Divide the wattage by 745.7. For example, 1,500 watts ÷ 745.7 = 2.01 horsepower.
Multiply kilowatts by 1.341, or convert kW to watts first (×1000) then divide by 745.7.
Mechanical, electrical, and metric horsepower were defined slightly differently. Mechanical (745.7 W) is most common for engines; electrical (746 W) for motors.
Almost — 1,000 watts is about 1.34 horsepower, since one HP is 745.7 watts.