# Difference between Horsepower and Torque

By: | Updated: Dec-7, 2017

Horsepower and torque are terms normally heard in auto and truck commercials as both are used to measure a vehicle’s performance on the road. But how are these words connected, really? This article seeks explain how.

## Summary Table

 Horsepower Torque Measure of the rate at which work is done Measure of the rotational force of an object Torque multiplied by RPM divided by 5,252 Horsepower multiplied by 5,252 divided by RPM Higher than torque at higher values Higher than horsepower at lower values

## Definitions Horsepower is a measurement of power; that is, the measurement of the rate at which work is done. The term was first used by James Watt, a Scottish engineer and inventor of the steam engine. He wanted to compare the power output of steam engines with that of draft horses as it was the amount energy people were familiar with at the time. It then became a standard measurement for the power output of engines and other machines. Watts came up with the idea that 1 horsepower is equal to a horse pulling a 330-lb load at a pace of 100 feet per minute; thus, 1 horsepower is equal to 33,000 foot-lbs. Later on, it expanded to cover the power produced by piston engines, electric motors, turbines, and various pieces of machinery. In exact mathematical terms, one horsepower is the amount of work required to move 550 lbs one foot in one second. A human is capable of maintaining about 0.1 horsepower while a small motor has an output of 10 horsepower. A jet engine is capable of generating 1,000 horsepower.

There are various standards and types of horsepower, and the two most commonly used are mechanical horsepower (i.e. imperial horsepower) and metric horsepower. Mechanical horsepower is equivalent to about 745.7 watts and was previously defined as equal to 550 foot-pounds per second. Metric horsepower is equivalent to about 735.5 watts and was originally defined as 75 kilogram-force per second.