Chain Length Calculation

Information Needed

CD = Center Distance (measured in inches for English or mm for Metric)
Z2 = number of teeth in large sprocket
Z1 = number of teeth in small sprocket
p = chain pitch (measured in inches for English or mm for Metric)


  1. Calculate C, where C = CD/p
  2. Calculate A, where A = Z1 + Z2
  3. Calculate S, where S = Z2 - Z1
  4. Refer to the adjacent table to find the T value for the calculated S value
  5. Chain Length in Pitches, CL = 2C + (A/2) + (T/C)

Note: If chain length is fractional round off to the nearest whole number of pitches. An even number of pitches is always preferable to an odd number which requires an offset section.

An offset section (also called a hunting link section) must be used when a chain contains an odd number of links. If an offset section is required, it will be necessary to increase the width of the chain by 25% to account for the reduced tensile strength of the offset.