What is horsepower? What is the electrical horsepower formula? How is the horsepower value of a car engine calculated? Read to find all the answers.
The Horse Connection
The Scottish engineer James Watt calculated the value of one horsepower by estimating the number of mill wheel rotations that a horse could complete in one hour. The unit is a relic from our horse-powered past.
One of the most vital parameters of a car engine is its horsepower. Before the advent of the industrial revolution, horses were widely used in most fields of human endeavor, including transport and agriculture.
Naturally, when the first machines like the steam engines came in, their power of operation was subjected to comparison with the muscle power provided by horses. That gave rise to the widely used unit of horsepower for power measurement. One electric horsepower (hp) equals 745.699872 W.
In an age where machine power was still struggling to gain acceptance, horsepower as a unit, was also an effective marketing tool. Though now replaced with the SI unit of ‘Watt’, as the standard international power measurement unit, it is still used in industries.
In what follows, the formula for calculating the horsepower of a car engine and an electric motor will be presented, along with calculators. Also listed, are conversion formulas for all the various versions of horsepower in use, around the world.