Which horsepower?
Mechanical (imperial) horsepower is 550 foot-pounds per second, 745.69987 W — the hp on US and UK car and motor ratings. Metric horsepower, written PS, CV or ch, is 735.49875 W, so a car advertised at 150 PS in Germany has 148 hp. Electric motors in metric countries are rated in kW directly. The calculator converts mechanical hp and shows PS on its own row; a 100 kW motor is 134.1 hp or 136.0 PS.
kilowatts = horsepower × 0.7457 | horsepower = kilowatts ÷ 0.7457
Rough conversion in your head
Multiply horsepower by ¾ for kilowatts: 200 hp → 150 kW (true 149.1). Multiply kilowatts by 1⅓ for horsepower: 75 kW → 100 hp (true 100.6). Electric vehicles are quoted in kW: a 150 kW motor is 201 hp. A one-horsepower motor draws about 746 W of mechanical output, and typically 900–1,000 W of electricity once losses are included.