Bike Chain Length Calculator
Work out how many links your bicycle chain needs from your chainrings, cassette and chainstay, using the sizing rules published by SRAM and Park Tool.
Drivetrain & Frame
Chain Length
116links
In inches:58 in (1473 mm)
Wrap, Big to Big
113.47links
Rounded to join:114
Maker's Addition
+2pitches
Derailleur range:42T
SRAM MTB, full suspension or idler (+2)
How the number is built
| Step | Links |
|---|---|
| Wrap the 32T ring and 52T cog at 452 mm (ASME B29.1) | 113.47 |
| Round up to where the chain ends can join (even count) | 114 |
| Add the sizing rule (2 pitches) | +2 |
| Chain length | 116 |
Suspension growth of 14 mm adds 2 links compared with sizing at the extended chainstay.
How Chain Makers Size a Bicycle Chain
Every maker starts from the chain wrapped around the largest chainring and the largest cog, bypassing the rear derailleur, and then adds a fixed number of links to cover the derailleur. The wrapped length comes from the same equation as the standard chain length calculator, with the chainstay as the center distance. To see how that distance changes with a different link count, try the chainstay growth tool.
1. Wrap, big to big
The calculator solves the length for the largest chainring and the largest cog at your chainstay length. For the example bike that is 113.47 links.
2. Join the ends
Chain joins inner link to outer link, so the length rounds up to an even count: 114 links here.
3. Add the maker's links
The maker's rule adds the extra links. A link here is one pitch, 1/2 inch, so two links is one inch of chain.
SRAM and Park Tool Sizing Rules
These are the rules the calculator applies, with their sources. Shimano gives its own figures from a different reference point, so check its dealer manual for a Shimano drivetrain. To decide whether an old chain is due for replacement, measure it with the chain stretch checker.
| Rule | Added pitches | Source |
|---|---|---|
| SRAM MTB, hardtail | +4 | SRAM Chains service manual, Eagle (non-T-Type) 12-speed and MTB 11 to 7-speed |
| SRAM MTB, full suspension or idler | +2 | SRAM Chains service manual, Eagle (non-T-Type) 12-speed and MTB 11 to 7-speed |
| SRAM road, 2x | +2 | SRAM Chains service manual, Road 12 / 11 / 10-speed |
| SRAM road, 1x | +4 | SRAM Chains service manual, Road 12 / 11 / 10-speed |
| Park Tool, cassette up to 36T | +2 | Park Tool, Chain Length Sizing, largest cog and largest chainring method |
| Park Tool, dedicated 1x with 42T+ cog | +4 | Park Tool, Chain Length Sizing, method for drivetrains with large rear cogs |
| Single-speed or hub gear | +0 | SRAM Chains service manual, Singlespeed 1x1; chain tension depends on the frame's dropouts or tensioner |
| SRAM T-Type Transmission | chart or app | SRAM Chains service manual, Full Mount Chain Length Guide and T-Type chain length chart |