Roller Chain Length Calculator

Inputs

Small sprocket teeth (N₁)

Large sprocket teeth (N₂)

Center distance (C)

Chain pitch (p)

Default result

Chain length (pitches)(L)

110

110 links — even, for a standard connecting link.

rounded up to an even number of links

Also computed

Chain length1,397mm

Exact pitches (before rounding)109.32

Rounded up by 0.68 pitch to reach an even 110 links.

Method notes 3 notes

Chain length is solved in pitches: L = 2C/p + (N₁+N₂)/2 + ((N₂−N₁)/2π)²·(p/C), then rounded up to an even number of links.
A roller chain needs an even number of pitches to close with a standard connecting link; an odd count forces a weaker offset (cranked) link.
Chain length = links × pitch. Rounding up adds a little slack — take it up by trimming the centre distance slightly or fitting a tensioner.