Example:
15 µW = 2.011533e-8 horsepower (550 ft·lbf/s)
1 µW = 1.341022e-9 horsepower (550 ft·lbf/s) | 1 horsepower (550 ft·lbf/s) = 745699871.5823 µW
Conversion Steps:
15 × (0.000001 / 745.699871582) = 2.011533e-8