Brake Horsepower (\( BHP \)):

\[ BHP = \frac{Pw}{\xi_p} \]

Where:

• \( BHP \) is the pump brake horsepower, in horsepower (hp).
• \( Pw \) is the water horsepower, in horsepower (hp).
• \( \xi_p \) is the pump efficiency, in decimal form.