Horsepower (boiler) to calories per second converter above calculates how many calories per second are in 'X' horsepower (boiler) (where 'X' is the number of horsepower (boiler) to convert to calories per second). In order to convert a value from horsepower (boiler) to calories per second (from hp to cal/s) just type the number of hp to be converted to cal/s and then click on the 'convert' button.