Indicated Horsepower (IHP):

\[ IHP = \frac{P \cdot L \cdot A \cdot N \cdot n}{33000 \cdot c} \]

Where:

• \(IHP\) is the indicated horsepower in horsepower (hp).
• \(P\) is the mean effective pressure in pounds per square inch (psi).
• \(L\) is the length of the stroke in feet (ft).
• \(A\) is the area of the bore in square inches (in²).
• \(N\) is the crankshaft speed in revolutions per minute (rpm).
• \(n\) is the number of cylinders.
• \(c\) is 2 for a four-stroke engine and 1 for a two-stroke engine.