Learn how to use the original and most popular gain ratios calculator for cyclists on the internet since 2009

The following instructions aim to assist you in effectively using our gain ratios calculator, ensuring a more seamless and informed experience.

1. Count the number of teeth on the front cog of your bicycle, and select this value in the picker labeled chainrings teeth.
2. Do the same on your rear cog for the picker labeled sprockets teeth.
3. Measure in millimeters the thickness of your rear tire across its tread when inflated, and select this value in the picker labeled tire thickness.
4. Do the same with the diameter of your rim up to its bead for the picker labeled rim diameter. Sometimes, a marking can also be found printed on the sidewall of the tire. If in doubt, please refer to our article explaining how these tire markings are designated.
5. Measure in millimeters the length of your crank arm from the center of its pedal to the center of your bottom bracket, and select this value in the picker labeled crank arms length. Sometimes, a marking can also be found engraved on the interior of the arms.

For more information about gain ratios, please visit our article answering common questions from the community.