Bicycle Chain Length Calculator

How to Use the Bike Chain Length Calculator

This chain length calculator helps determine the correct chain length for your bike. Whether you're replacing an old chain with a new chain or checking your current chain length, this tool provides accurate measurements. Using a chain tool and checking against the original chain can help ensure proper installation.

The Formula to Calculate Chain Length

The chain length calculator uses the following formula to determine the chain length:

Understanding Chain Components

A bicycle chain consists of inner plates and outer plates connected by two rivets. The master link (also called a quick link) joins the chain ends together. Each link measures approximately one inch in length, and the total chain consists of multiple inner and outer plates working together.

Input Parameters

• 1

  Chainstay Length

  The distance from the center of the bottom bracket to the center of the rear axle.

• 2

  Largest Front Chainring

  The number of teeth on the largest chainring at the front.

• 3

  Largest Rear Sprocket

  The number of teeth on the largest sprocket on the rear cassette.

Calculation Process of the Chain Length Calculator

• 1

  Apply Formula

  The calculator takes the input values and applies them to the formula.

• 2

  Unit Conversion

  If the chainstay length is provided in millimeters, it's converted to inches (1 inch = 25.4 mm).

• 3

  Calculate Chain Length

  The result (L) gives the chain length in inches.

• 4

  Calculate Number of Chain Links

  The number of chain links is calculated by dividing the chain length by 0.5 (as each link is typically 0.5 inches long).

• 5

  Round Up

  The number of links is rounded up to the nearest even number to ensure a complete chain.

Output

The calculator provides two main outputs:

• 1

  Total Correct Chain Length

  The estimated length of the chain in inches or centimeters.

• 2

  Number of Chain Links

  The recommended number of chain links for your new chain, rounded to an even number.

Important Notes

• 1

  Estimate Only

  This calculation provides an estimate and should be used as a starting point.

• 2

  Manufacturer Guidelines

  Always refer to your bicycle manufacturer's guidelines for the most accurate chain length.

• 3

  Additional Factors

  Consider factors like suspension design and specific drivetrain requirements when determining the final chain length.

• 4

  Err on the Side of Longer

  It's generally better to err on the side of a slightly longer chain, as it can be shortened if necessary.

Use this calculator as a helpful tool in determining your bike's chain length and chain links, but always double-check with professional resources or a bike mechanic for the best results.