horsepower

Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are the imperial horsepower, abbreviated hp or bhp, which is about 745.7 watts, and the metric horsepower, also represented as cv or PS, which is approximately 735.5 watts. The electric horsepower, hpE, is exactly 746 watts, while the boiler horsepower is 9809.5 or 9811 watts, depending on the exact year.