Horsepower Formula

Before the advent of the industrial revolution, horses were widely in used in most fields of human endeavor including transport and agriculture. Naturally, when the first machines like the steam engines were invented, the power of operation they provided was compared with the muscle power provided by horses. That gave rise to the widely used unit of horsepower for measurement of power. In this article, you will find information about the horsepower formula.

What is Horsepower?

Power is defined as the rate of energy converted or work done per unit time. Horsepower is a unit of power that has nothing to do with horses, other than the fact that it has an etymological and historical origin in comparison of machine power with the muscle power of horses. It was first used in case of steam engine power output measurement in comparison with the power provided by draft horses. Horsepower is not an internationally accepted SI unit. In fact there are many units by the name of horsepower used to measure the power output of different types. Have a look at how a steam engine works.

It is interesting to know how James Watt and his contemporaries calculated the value of one horsepower. He actually estimated the number of mill wheel rotations that a horse could make in one hour and by making an estimate of the force applied by a horse, he came up with a number for horsepower. It was befitting then that the standard unit of power was named after Watt. Horsepower was important as a unit of power in those days, as a marketing tool, as it was an age of transition when horsepower was being replaced by machine power.

Formula For Horsepower

If you are wondering how to calculate horsepower, then all you need to know is the appropriate horsepower conversion formula. Here are the main horsepower formulas for your reference.

Electrical Horsepower Formula
The most commonly used horsepower unit is electrical horsepower. The unit is used to measure the input and output of many electrical appliances including electric motors. Here is the formula for electrical horse power.

1 Electrical Horsepower = 746 Watts

Mechanical Horse Power Formula
Mechanical power of any kind can be quantified by using the mechanical horse power as a unit. Here is the conversion formula for mechanical horsepower.

1 Mechanical Horsepower = 745.699872 Watts = 550 ft.lb/s

Metric Horse Power Formula
Metric horsepower is a unit of power that was first used in Germany and since then has been used in many other European, as well as Asian countries. It slightly differs in value from the mechanical horsepower unit and is denoted variously by abbreviations like CV, PS, hk, ch and pk which are derived from names given to horse power in various languages. The powers of car engines of European make is often quoted in metric horse power. Here is the metric horsepower conversion formula.

1 Metric Horsepower = 735.49875 Watts

Boiler Horse Power Formula
Boiler horse power (BHP) is a power unit used for measuring the power output of boilers, widely used in the past, but now confined to North America. The boiler horsepower conversion formula is as follows.

1 Boiler Horsepower = 9,809.5 Watts

Hydraulic Horse Power Formula
One more unit used for power measurement used in hydraulics is hydraulic horsepower. The hydraulic horsepower conversion formula is as follows.

1 Hydraulic Horsepower = 745.699872 Watts

Read more on:

• What is BHP (Brake Horsepower)
• What is Horsepower
• Physics Formulas List

Hope the information about horsepower formulas provided here is useful. Quantifying things is important in science and technology and units like horsepower are needed for the same purpose.