The formula to calculate the length of the driving chain is:

\[ L = 2C_p + \frac{T + t}{2} + \frac{T - t}{2 \pi C_p} \]

Where:

• \(L\) is the length of the chain in pitches.
• \(C_p\) is the center to center distance in pitches.
• \(T\) is the number of teeth on the larger sprocket.
• \(t\) is the number of teeth on the smaller sprocket.