Watt hours to horsepower-hour converter above calculates how many horsepower-hour are in 'X' watt hours (where 'X' is the number of watt hours to convert to horsepower-hour). In order to convert a value from watt hours to horsepower-hour (from Wh to hph) simply type the number of Wh to be converted to hph and then click on the 'convert' button.