# Horsepower Calculator Horsepower refers to a unit of power that is equal to 550 foot-pounds (745.7 watts). Horsepower is the power of an engine that is measured. Horsepower is defined as work done over time. Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The SI unit of horsepower is Watt. Horsepower was first used by James Watt, who employed it to compare the power of steam engines with that of horses.

Horsepower Calculator

pound-foot
revolution per minute
Watt

Formula

Rotating Horsepower (HP) = T * (N / 5252) Watt

Where,
T - Torque
N - Speed

Horsepower (hp or HP) is the name of several non-SI units of power (watt). It was originally defined to allow the output of steam engines to be measured and compared with the power output of draft horses.

Example:
Calculate the Rotating Horsepower for the given details.
Torque = 5 pound-foot
Speed = 10 revolution per minute

Solution:
Apply Formula:
Rotating Horsepower (HP) = T * (N / 5252) Watt
Rotating Horsepower (HP) = 5*(10/5252)
Rotating Horsepower (HP) = 5* (0.00190)
Rotating Horsepower (HP) = 0.00952018278750952 Watt