Tool
Motorcycle Chain Length Calculator
The link count uses the standard two-sprocket formula. You enter pitch, front teeth, rear teeth, and the center-to-center distance between shafts. 520, 525, and 530 all use a 0.625 inch pitch; they differ in width, not in pitch.
Recommended even links
—
When to use this calculator
Use it when you are changing sprocket size and you need a first estimate of chain length. Confirm slack on the motorcycle after assembly. The formula does not replace a shop measurement with the axle in the adjusters.
The exact link figure is usually not an integer. The recommended count is that figure rounded up to the next even number so a standard connecting link can close the chain.
This is not a wear, tensile, or replacement-interval tool. It does not choose 520 versus 530 for you.
Zero teeth, zero pitch, or a zero center distance produces a field error.
Worked chains
The default is a mid-size street swingarm. The even link count is the number to compare with the chain you already have on the bike.
A smaller front sprocket changes the exact figure slightly. Check whether the rounded even count actually moves before you buy a different length.
Switching size from 520 to 525 or 530 should not change the link math, because pitch stays 0.625 inches.
Technical questions
What formula does the calculator use?
Links ≈ 2 × (C ÷ P) + (N + n) ÷ 2 + ((N − n) ÷ 2π)² × (P ÷ C). C is center distance, P is pitch, N is rear teeth, and n is front teeth.
Why are 520, 525, and 530 the same pitch?
The first digit is the pitch in eighths of an inch. All three start with 5, so pitch is 5/8 inch. The remaining digits describe width.
Should I round up or down?
This page rounds the exact figure up to the next even count. If your axle still has room to move forward, a shop may choose a different even number after a test fit.