Thanks for using the BMX Chain Calculator, the most comprehensive online tool for calculating BMX chain lengths. Ever wondered how many links you need for your new chain or the exact chainstay length of your bike after installing the chain? Find out here!
Choose Sprocket Size
Choose Driver Size
Choose Desired Chainstay Length
| Sprocket | Driver | Chainstay | Exact | Chain | Halflink |
|---|---|---|---|---|---|
| 25T | 8T | 12.50" | 12.55" | 67 Links | Yes |
| 25T | 8T | 12.75" | 12.80" | 68 Links | No |
| 25T | 8T | 13.00" | 13.06" | 69 Links | Yes |
| 25T | 8T | 13.25" | 13.31" | 70 Links | No |
| 25T | 8T | 13.50" | 13.56" | 71 Links | Yes |
| 25T | 8T | 13.75" | 13.81" | 72 Links | No |
| 25T | 8T | 14.00" | 14.06" | 73 Links | Yes |
| 25T | 8T | 14.25" | 14.31" | 74 Links | No |
| 25T | 8T | 14.50" | 14.56" | 75 Links | Yes |
| 25T | 8T | 14.75" | 14.81" | 76 Links | No |
| 25T | 9T | 12.50" | 12.43" | 67 Links | Yes |
| 25T | 9T | 12.75" | 12.69" | 68 Links | No |
| 25T | 9T | 13.00" | 12.94" | 69 Links | Yes |
| 25T | 9T | 13.25" | 13.19" | 70 Links | No |
| 25T | 9T | 13.50" | 13.44" | 71 Links | Yes |
| 25T | 9T | 13.75" | 13.69" | 72 Links | No |
| 25T | 9T | 14.00" | 13.94" | 73 Links | Yes |
| 25T | 9T | 14.25" | 14.19" | 74 Links | No |
| 25T | 9T | 14.50" | 14.44" | 75 Links | Yes |
| 25T | 9T | 14.75" | 14.69" | 76 Links | No |
| 25T | 10T | 12.50" | 12.57" | 68 Links | No |
| 25T | 10T | 12.75" | 12.82" | 69 Links | Yes |
| 25T | 10T | 13.00" | 13.07" | 70 Links | No |
| 25T | 10T | 13.25" | 13.32" | 71 Links | Yes |
| 25T | 10T | 13.50" | 13.57" | 72 Links | No |
| 25T | 10T | 13.75" | 13.82" | 73 Links | Yes |
| 25T | 10T | 14.00" | 14.07" | 74 Links | No |
| 25T | 10T | 14.25" | 14.33" | 75 Links | Yes |
| 25T | 10T | 14.50" | 14.58" | 76 Links | No |
| 25T | 10T | 14.75" | 14.83" | 77 Links | Yes |
| 25T | 11T | 12.50" | 12.45" | 68 Links | No |
| 25T | 11T | 12.75" | 12.70" | 69 Links | Yes |
| 25T | 11T | 13.00" | 12.95" | 70 Links | No |
| 25T | 11T | 13.25" | 13.20" | 71 Links | Yes |
| 25T | 11T | 13.50" | 13.45" | 72 Links | No |
| 25T | 11T | 13.75" | 13.70" | 73 Links | Yes |
| 25T | 11T | 14.00" | 13.96" | 74 Links | No |
| 25T | 11T | 14.25" | 14.21" | 75 Links | Yes |
| 25T | 11T | 14.50" | 14.46" | 76 Links | No |
| 25T | 11T | 14.75" | 14.71" | 77 Links | Yes |
| 28T | 8T | 12.50" | 12.65" | 69 Links | Yes |
| 28T | 8T | 12.75" | 12.90" | 70 Links | No |
| 28T | 8T | 13.00" | 13.15" | 71 Links | Yes |
| 28T | 8T | 13.25" | 13.41" | 72 Links | No |
| 28T | 8T | 13.50" | 13.66" | 73 Links | Yes |
| 28T | 8T | 13.75" | 13.91" | 74 Links | No |
| 28T | 8T | 14.00" | 14.16" | 75 Links | Yes |
| 28T | 8T | 14.25" | 14.41" | 76 Links | No |
| 28T | 8T | 14.50" | 14.66" | 77 Links | Yes |
| 28T | 8T | 14.75" | 14.92" | 78 Links | No |
| 28T | 9T | 12.50" | 12.53" | 69 Links | Yes |
| 28T | 9T | 12.75" | 12.79" | 70 Links | No |
| 28T | 9T | 13.00" | 13.04" | 71 Links | Yes |
| 28T | 9T | 13.25" | 13.29" | 72 Links | No |
| 28T | 9T | 13.50" | 13.54" | 73 Links | Yes |
| 28T | 9T | 13.75" | 13.79" | 74 Links | No |
| 28T | 9T | 14.00" | 14.04" | 75 Links | Yes |
| 28T | 9T | 14.25" | 14.30" | 76 Links | No |
| 28T | 9T | 14.50" | 14.55" | 77 Links | Yes |
| 28T | 9T | 14.75" | 14.80" | 78 Links | No |
| 28T | 10T | 12.50" | 12.67" | 70 Links | No |
| 28T | 10T | 12.75" | 12.92" | 71 Links | Yes |
| 28T | 10T | 13.00" | 13.17" | 72 Links | No |
| 28T | 10T | 13.25" | 13.42" | 73 Links | Yes |
| 28T | 10T | 13.50" | 13.68" | 74 Links | No |
| 28T | 10T | 13.75" | 13.93" | 75 Links | Yes |
| 28T | 10T | 14.00" | 14.18" | 76 Links | No |
| 28T | 10T | 14.25" | 14.43" | 77 Links | Yes |
| 28T | 10T | 14.50" | 14.68" | 78 Links | No |
| 28T | 10T | 14.75" | 14.93" | 79 Links | Yes |
| 28T | 11T | 12.50" | 12.55" | 70 Links | No |
| 28T | 11T | 12.75" | 12.80" | 71 Links | Yes |
| 28T | 11T | 13.00" | 13.06" | 72 Links | No |
| 28T | 11T | 13.25" | 13.31" | 73 Links | Yes |
| 28T | 11T | 13.50" | 13.56" | 74 Links | No |
| 28T | 11T | 13.75" | 13.81" | 75 Links | Yes |
| 28T | 11T | 14.00" | 14.06" | 76 Links | No |
| 28T | 11T | 14.25" | 14.31" | 77 Links | Yes |
| 28T | 11T | 14.50" | 14.56" | 78 Links | No |
| 28T | 11T | 14.75" | 14.81" | 79 Links | Yes |
| 30T | 8T | 12.50" | 12.63" | 70 Links | No |
| 30T | 8T | 12.75" | 12.88" | 71 Links | Yes |
| 30T | 8T | 13.00" | 13.13" | 72 Links | No |
| 30T | 8T | 13.25" | 13.39" | 73 Links | Yes |
| 30T | 8T | 13.50" | 13.64" | 74 Links | No |
| 30T | 8T | 13.75" | 13.89" | 75 Links | Yes |
| 30T | 8T | 14.00" | 14.14" | 76 Links | No |
| 30T | 8T | 14.25" | 14.39" | 77 Links | Yes |
| 30T | 8T | 14.50" | 14.65" | 78 Links | No |
| 30T | 8T | 14.75" | 14.90" | 79 Links | Yes |
| 30T | 9T | 12.50" | 12.51" | 70 Links | No |
| 30T | 9T | 12.75" | 12.77" | 71 Links | Yes |
| 30T | 9T | 13.00" | 13.02" | 72 Links | No |
| 30T | 9T | 13.25" | 13.27" | 73 Links | Yes |
| 30T | 9T | 13.50" | 13.52" | 74 Links | No |
| 30T | 9T | 13.75" | 13.77" | 75 Links | Yes |
| 30T | 9T | 14.00" | 14.03" | 76 Links | No |
| 30T | 9T | 14.25" | 14.28" | 77 Links | Yes |
| 30T | 9T | 14.50" | 14.53" | 78 Links | No |
| 30T | 9T | 14.75" | 14.78" | 79 Links | Yes |
| 30T | 10T | 12.50" | 12.65" | 71 Links | Yes |
| 30T | 10T | 12.75" | 12.90" | 72 Links | No |
| 30T | 10T | 13.00" | 13.15" | 73 Links | Yes |
| 30T | 10T | 13.25" | 13.41" | 74 Links | No |
| 30T | 10T | 13.50" | 13.66" | 75 Links | Yes |
| 30T | 10T | 13.75" | 13.91" | 76 Links | No |
| 30T | 10T | 14.00" | 14.16" | 77 Links | Yes |
| 30T | 10T | 14.25" | 14.41" | 78 Links | No |
| 30T | 10T | 14.50" | 14.66" | 79 Links | Yes |
| 30T | 10T | 14.75" | 14.92" | 80 Links | No |
| 30T | 11T | 12.50" | 12.53" | 71 Links | Yes |
| 30T | 11T | 12.75" | 12.79" | 72 Links | No |
| 30T | 11T | 13.00" | 13.04" | 73 Links | Yes |
| 30T | 11T | 13.25" | 13.29" | 74 Links | No |
| 30T | 11T | 13.50" | 13.54" | 75 Links | Yes |
| 30T | 11T | 13.75" | 13.79" | 76 Links | No |
| 30T | 11T | 14.00" | 14.04" | 77 Links | Yes |
| 30T | 11T | 14.25" | 14.30" | 78 Links | No |
| 30T | 11T | 14.50" | 14.55" | 79 Links | Yes |
| 30T | 11T | 14.75" | 14.80" | 80 Links | No |
Tips
Traditional chain designs (e.g., 510) require two links to be added or removed at a time. Half-link chains, however, are designed so that only one link needs to be added or removed at a time, offering more adjustability. Alternatively, a single half-link can also be added to a traditional chain.
An even number of links (e.g., 70) means a traditional chain can be used without a half-link. An odd number of links (e.g., 71) means a half-link chain will be needed, or you can add a single half-link to a traditional chain.
The number of links in the chain determines the exact chainstay length of your bike. Since each link is 1/2″ long, adding or removing a single link will adjust the chainstay length by approximately 1/4″. Adding or removing a pair of links on a traditional chain will adjust the length by 1/2″.
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