Example:
15 horsepower (550 ft·lbf/s) = 1.11855e-11 PW
1 horsepower (550 ft·lbf/s) = 7.456999e-13 PW | 1 PW = 1.341022e+12 horsepower (550 ft·lbf/s)
Conversion Steps:
15 × (745.699871582 / 1e+15) = 1.11855e-11