What is a horsepower?

Watt (W): SI unit of power
Kilowatt (kW): 1000 Watts
Horsepower (hp): Imperial unit, ~745.7 Watts
BTU/hour: British Thermal Unit per hour

1 horsepower = 745.7 Watts. It was historically defined as the power needed to lift 75 kg one meter in one second.

How much power does a light bulb use?

A typical LED bulb uses 9-12 W, while an incandescent bulb uses 40-60 W for the same brightness.

Convert between different power units: Watt, kilowatt, horsepower, and more.

Convert between various power units. Power is the rate of energy transfer or consumption.

A typical car engine produces about 100 hp. Convert to kilowatts:

1 horsepower = 745.7 Watts. It was historically defined as the power needed to lift 75 kg one meter in one second.
A typical LED bulb uses 9-12 W, while an incandescent bulb uses 40-60 W for the same brightness.