Horsepower to Watts Converter
Enter a value to instantly convert between power units.
1 Horsepower (mech) = 745.6999 Watt
Key Formulas
Kilowatt → Horsepower (mech)
hp = kW × 1.34102Horsepower (mech) → Kilowatt
kW = hp × 0.7457Watt → Kilowatt
kW = W × 0.001Kilowatt → Watt
W = kW × 1000Formula
W = hp × 745.69987Mechanical horsepower is the traditional unit for engines, motors, and power tools — but electrical engineers, EV manufacturers, and solar system designers work in watts. When a pump requires a 5 hp motor and you're ordering an electric motor with a watt rating, you need 5 × 745.7 = 3,728.5 W to know the required power. The same applies when sizing a generator for a gasoline-rated load: a 10 hp engine produces 7,457 W, so you need at least a 7.5 kW generator.
Source: NIST SP 811, Table B.8
Last reviewed: · see our methodology
Frequently Asked Questions
Real-World Examples
A 0.5 hp sump pump motor draws about 373 W — a small but critical load during heavy rain events, relevant for generator sizing.
0.5 hp = 372.8 W
A 1 hp pool pump motor draws 746 W — running 8 hours a day adds about 2 kWh to your electricity bill daily.
1 hp = 745.7 W
A 5 hp air compressor motor draws 3,729 W — requires a 20 A, 240 V circuit and accounts for roughly 30% of a workshop's electrical demand.
5 hp = 3728.5 W
A 200 hp car engine at full throttle produces 149,140 W = 149 kW — typical for a mid-range performance sedan at peak power.
200 hp = 149140 W