Horsepower (hp)

The measure of rate of work. One horsepower is equivalent to lifting 33,000 pounds to a height of 1 ft. in 1 min. The horsepower of a motor is expressed as a function of torque and speed. For motors, the following approximate formula may be used:

hp = (T × rpm) / 5250

where hp is horsepower; T is torque (in. lb. ft.); and rpm is revolutions per minute.

One horsepower is equivalent to 745.7 W.

See also Adiabatic Horsepower; Constant Horsepower; Gas Horsepower; Indicated Horsepower; Unloaded Horsepower; Valve Loss Horsepower; Water Horsepower.