Cycling & gearing
Bike cassette gear step calculator.
Type in the cogs on your cassette and your chainring to see how big each shift is, how far your cadence moves when you change gear, and the cassette’s overall range. Runs in your browser.
Drivetrain
Gear steps
Fill the form and press Calculate.
Worked example
For cogs 11, 12, 13, 14, 15, 17, 19, 21 and 24 with a 50-tooth chainring, going from the 11 to the 12 changes the gear by 12 ÷ 11 − 1 = 9.1%. At the same speed your cadence rises 9.1% shifting to the easier cog, or falls 1 − 11 ÷ 12 = 8.3% shifting back. The biggest jump on this set is 14.3%, from the 21 to the 24; the cassette range is 24 ÷ 11 = 218%, and the gear ratios run from 4.55 down to 2.08.
How it works
Gear ratio = chainring teeth ÷ cog teeth (Sheldon Brown). The jump between two cogs is the larger cog divided by the smaller, minus 1. Because speed equals cadence times ratio, a shift at constant speed changes cadence by that same factor. Range is the largest cog divided by the smallest, expressed as a percentage. Big steps near the easy end of a cassette are normal, since each extra tooth is a smaller share of the cog on the bigger sprockets.
The figures are arithmetic on the tooth counts you enter; they do not depend on a product or brand.
Sources
Retrieved 2026-10-16. The ratio definition is Sheldon Brown’s; the jump, cadence and range figures are simple arithmetic on the cogs you enter.
FAQ
How do I calculate the jump between cassette gears?
Divide the larger cog by the smaller and subtract 1. From an 11 to a 12 tooth cog that is 12 ÷ 11 − 1, or 9.1%.
What is cassette range?
The largest cog divided by the smallest, as a percentage. An 11-24 cassette is 24 ÷ 11 = 218%. Wider range means a bigger spread between your hardest and easiest gear.
How much does my cadence change when I shift?
At the same speed, shifting to the next easier cog raises cadence by the jump (9.1% from 11 to 12 teeth), and shifting back lowers it by 1 − smaller ÷ larger (8.3%).
Why are the jumps bigger on the large cogs?
Because each added tooth is a smaller share of a large cog, wide-range cassettes usually add several teeth at a time at the easy end, which makes the jumps larger there.
Do I need to enter my chainring?
It only sets the ratio column. The percentage jumps and range depend on the cogs alone.
Disclaimer
Arithmetic on the tooth counts you enter. Check your drivetrain maker’s compatibility before changing parts.