Gear ratio calculator
Ratio, development (metres per pedal turn), gear inches and speed at a cadence, for one cog or a whole cassette.
The pros' groupsets, team by team, where a source gives them: what the WorldTeams ride.
How this is calculated
ratio = chainring / cog · development (m) = ratio × wheel circumference (mm) / 1000 · gear inches = ratio × (circumference / π) / 25.4 · speed (km/h) = development × cadence × 60 / 1000
Circumferences are the tyre makers' and computer makers' approximate values; a roll-out under your own weight is more exact. Sources: Sheldon Brown, Gain Ratios — https://www.sheldonbrown.com/gain.html ; Wikipedia, Bicycle gearing — https://en.wikipedia.org/wiki/Bicycle_gearing; CatEye — https://cateye.com/intl/support/qa_search/001772.html ; Garmin — https://www8.garmin.com/manuals/webhelp/fenix3/EN-US/GUID-DB0BC20A-DADF-41EB-A61C-14BEC158B43C.html (700x38C/40C Garmin only; 700x30C CatEye 2146, Garmin 2170 treated as error).
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