Horsepower to Watts Converter

The car's spec sheet says 150 PS, the water pump is rated in watts, and you need to compare the two. Or you are sizing a breaker and the only figure on the motor plate is in horsepower. Metric horsepower is a leftover from the steam era that never left vehicle brochures, written as cv in Brazil and PS in Germany. Enter the figure and read the equivalent in watts.

The factor applied is 735.5 W per unit. The exact definition is 735.49875 W, the power needed to lift 75 kg one meter per second, so the rounding is invisible in practice. The confusing part: metric horsepower (cv, PS, cheval-vapeur) is not the same as the imperial horsepower used in the US and UK, which is 745.7 W. A 100 hp engine is 101.4 metric horsepower.

When comparing two cars, check which unit each brochure uses, since a 1.4% gap is enough to flip the ranking of similar models. For electrical sizing, remember this watt figure is mechanical output at the shaft. The draw from the mains is higher, because no motor is 100% efficient: a 1 cv motor at 80% efficiency pulls roughly 920 W. The conversion happens in your browser.