Chain Length Calculator

| Added in Automotive

Formula

The chain length is calculated using the following formula:

$$L = 2C + \frac{F}{4} + \frac{R}{4} + 1$$

Where:

  • L is the chain length
  • C is the chain stay length
  • F is the number of teeth on the front chainring
  • R is the number of teeth on the rear cog

Example Calculation

Given:

  • Chain Stay (C) = 17 in
  • Front Teeth (F) = 34
  • Rear Teeth (R) = 24

Calculation:

$$L = 2 \times 17 + \frac{34}{4} + \frac{24}{4} + 1$$

$$L = 34 + 8.5 + 6 + 1 = 49.5$$

Result: The chain length is 49.5 inches.