Chain size converter

Roller Chain Size Converter

Convert ANSI roller chain sizes such as #25, #35, #40, #50, #60, #80, and #100 into pitch, roller width, roller diameter, and metric dimensions. Handy for checking sprockets, replacement chain, go-karts, machinery, conveyors, and farm equipment.

Convert a roller chain size

Pick a standard ANSI size or enter a pitch to find the closest chain family.

Chain size#40 roller chain

1/2 inch pitch industrial roller chain.

Pitch0.500 in · 12.70 mm
Roller width0.312 in · 7.92 mm
Roller diameter0.312 in · 7.92 mm

#40 chain is a common 1/2 inch pitch roller chain. Always confirm sprocket tooth width, strand count, and application before replacing chain.

How roller chain numbers convert

Many ANSI roller chain sizes encode the pitch in eighths of an inch. A #40 chain has a pitch of 4/8 inch, which is 1/2 inch or 12.70 mm. A #60 chain has a pitch of 6/8 inch, which is 3/4 inch or 19.05 mm.

The second digit often gives the chain series and roller style. This converter focuses on common single-strand ANSI roller chain dimensions for quick identification.

Use the chart before ordering chain

Pitch is the distance from one pin center to the next. Roller width and roller diameter help separate similar-looking sizes. If an old chain is worn, measure several links and divide by the number of pitches for a cleaner estimate.

For motorcycles, bicycles, leaf chain, metric ISO chain, or double-strand chain, match the full marked chain number rather than pitch alone.

ANSI roller chain size chart

SizePitchRoller widthRoller diameterTypical use

Roller chain size FAQ

What does #40 chain mean?

#40 roller chain is a common ANSI chain with 1/2 inch pitch. Its roller width and roller diameter are each about 5/16 inch.

What is the pitch of #35 chain?

#35 chain has 3/8 inch pitch, which equals 9.525 mm.

Can I replace chain by matching pitch only?

No. Pitch is the first check, but roller width, sprocket width, roller diameter, tensile rating, strand count, and application also matter.