Brake Horsepower (BHP):

\[ BHP = IHP \cdot \xi_m \quad \text{or} \quad BHP = IHP - FHP \]

Where:

• \(BHP\) is the brake horsepower in horsepower (hp).
• \(IHP\) is the indicated horsepower in horsepower (hp).
• \(\xi_m\) is the engine mechanical efficiency (decimal).
• \(FHP\) is the friction horsepower in horsepower (hp).