HP to kW Converter

Two spec sheets on screen: one rates the engine in HP, the other in kW, the norm for electric motors and much of Europe. Pick the direction, type the number and you are done: 150 HP is 111.855 kW, and 100 kW is 134.1 HP. It is the conversion that shows up whenever you compare an imported car with a local one, or a pump with a conveyor motor.

Here is the catch: there is more than one horsepower. This page uses mechanical HP at 745.7 W. European and Brazilian car figures are usually in metric horsepower, PS or cv, worth 735.5 W, about 1.4% less. An engine sold as 150 PS makes 110.3 kW, not the 111.9 kW you would get here. That is exactly why the same engine is quoted as 148 hp in one magazine and 150 PS in another.

Use this page when the source says hp or bhp; when it says PS or cv, the site has a converter covering all three units at once. Remember this is mechanical shaft power, not the electrical power the motor draws: at 90% efficiency, a 10 kW motor at the shaft pulls around 11.1 kW from the supply. The calculation happens in your browser, with nothing sent anywhere.