Chain Length Calculator
Estimate roller-chain length and the centre distance for an even link count.
A QUICK WALKTHROUGH
How to use this tool
- Enter both sprocket tooth counts, centre distance and chain pitch.
- Calculate the even link count, chain length and fitted centre distance.
Formula and scope
x = (t1+t2)/2 + 2C/p + (t2−t1)²p/(4π²C); round up to an even link count. For fitted spacing, y=(X+√(X²−4k))/2, X=links−(t1+t2)/2, k=(t2−t1)²/(4π²), Cfit=py/2.
Scope
ANSI roller-chain estimate. Even link counts are typical; an odd count may need a weaker offset link. Chain elongation and tension adjustment change fit. Verify the actual centre spacing and use a tensioner or adjustment allowance.
GOOD TO KNOW
Common questions
Is the calculated chain ready to install?
No. Check manufacturer data, sprocket geometry and available centre adjustment before selecting a chain.