Gear Ratio Calculator

Select your groupset and instantly see every gear, speed, development and steps.

Road BikesMountain BikesGravel Bikes
The Tour de France starts Saturday 4 July — browse every climb and plan the gearing you'd need. TDF 2026 climbs →
Configure Groupset
50T
34T
90rpm
60 rpm130 rpm
Top Speed
Lowest Speed
Speed Range
Gear Development
Metres per crank revolution · slowest left, fastest right · hover for speed at 90 rpm
Big ring
Small ring
Select a groupset to see your gear chart
Gear Breakdown
Dimmed gears are cross-chain — avoid for drivetrain longevity
Reading the Chart

Coloured bands — the band below each curve grades the size of the jump between one gear and the next. The same step % appears between the gear cards below.

under 10% — smooth, barely felt shift
10–14% — noticeable step
14% or more — big jump in cadence

Development curve — each dot is one gear, plotted by how far the bike travels per crank revolution. The curve rises left to right: slowest gear on the left, fastest on the right.

Two lines — the upper curve is your big ring, the lower is your small ring. Where they overlap in height is the speed range covered by both rings.

× marks — cross-chain gears to avoid. Big ring with the two largest cogs, or small ring with the two smallest, angles the chain across the cassette and accelerates wear.