how many watts make a horsepower
* A metric horsepower of 75 kgf-m per second is equivalent to 735.499 watts. * A boiler horsepower is used for rating steam boilers and is equivalent to 34.5 pounds of water evaporated per hour at 212 degrees Fahrenheit, or 9,809.5 watts. * One horsepower for rating electric motors is equal to 746 watts.