Example:
15 horsepower (550 ft·lbf/s) = 1.11855e-8 TW
1 horsepower (550 ft·lbf/s) = 7.456999e-10 TW | 1 TW = 1.341022e+9 horsepower (550 ft·lbf/s)
Conversion Steps:
15 × (745.699871582 / 1e+12) = 1.11855e-8