Gear ratio calculator

A smaller front or larger rear sprocket gives better acceleration but a lower top speed. The calculator shows the change.

Result

Results are calculated estimates. Always check your vehicle manufacturer's instructions.

Matching products: Gears Gears and chain kits

Enter the number of teeth on your current sprockets (front and rear).
Enter the new numbers of teeth.
Optionally enter your current top speed – the calculator works out the new one (at the same engine revs).

One tooth at the front vs. the rear?

One tooth at the front changes the ratio about as much as 3 teeth at the rear.

Do I need a new chain?

If the number of teeth changes by more than a couple, you may need a longer or shorter chain. Replace a worn chain together with the sprockets.