Bike gear calculator
This bike gear calculator lists every combination of chainring and cassette cog, sorted from easiest to hardest, with the ratio, development, gear inches and speed at your cadence for each. Enter your chainrings and cassette, pick a wheel and tyre size, set a cadence, and see exactly how far each gear moves you per pedal stroke, so you can plan gear choice before a climb or a flat time trial.
Top gear speed
51.7km/h
All gear combinations
| Chainring | Cog | Ratio | Development (m) | Gear inches | Speed (km/h) |
|---|---|---|---|---|---|
| 34 | 28 | 1.21 | 2.56 | 32.0 | 13.8 |
| 34 | 24 | 1.42 | 2.98 | 37.4 | 16.1 |
| 34 | 21 | 1.62 | 3.41 | 42.7 | 18.4 |
| 50 | 28 | 1.79 | 3.76 | 47.1 | 20.3 |
| 34 | 19 | 1.79 | 3.77 | 47.2 | 20.3 |
| 34 | 17 | 2.00 | 4.21 | 52.8 | 22.7 |
| 50 | 24 | 2.08 | 4.39 | 55.0 | 23.7 |
| 34 | 15 | 2.27 | 4.77 | 59.8 | 25.8 |
| 50 | 21 | 2.38 | 5.01 | 62.8 | 27.1 |
| 34 | 14 | 2.43 | 5.11 | 64.1 | 27.6 |
| 34 | 13 | 2.62 | 5.51 | 69.0 | 29.7 |
| 50 | 19 | 2.63 | 5.54 | 69.4 | 29.9 |
| 34 | 12 | 2.83 | 5.96 | 74.7 | 32.2 |
| 50 | 17 | 2.94 | 6.19 | 77.6 | 33.4 |
| 34 | 11 | 3.09 | 6.51 | 81.5 | 35.1 |
| 50 | 15 | 3.33 | 7.02 | 87.9 | 37.9 |
| 50 | 14 | 3.57 | 7.52 | 94.2 | 40.6 |
| 50 | 13 | 3.85 | 8.10 | 101.5 | 43.7 |
| 50 | 12 | 4.17 | 8.77 | 109.9 | 47.4 |
| 50 | 11 | 4.55 | 9.57 | 119.9 | 51.7 |
How it works
Development is the distance the bike travels for one full crank revolution: wheel circumference multiplied by the gear ratio, chainring teeth divided by cog teeth. It's the most direct measure of how far a gear moves you, independent of cadence.
Gear inches is an older, wheel-diameter-based unit from the days of penny-farthings, still used by some riders and gear charts: development divided by pi and converted to inches, giving an equivalent front-wheel diameter for a direct-drive bike.
Speed at your chosen cadence comes directly from development: distance per pedal stroke multiplied by strokes per minute, converted to km/h, which is why the same gear produces a different speed at 70 rpm than at 100 rpm.
Frequently asked questions
What is gear development in cycling?
Development is the distance your bike travels for one complete pedal revolution, combining your gear ratio with your wheel and tyre size. A bigger chainring, smaller cog or larger wheel all increase development, meaning more distance and more resistance per pedal stroke.
How do I know which gear to use on a climb?
Pick a gear whose speed at your comfortable climbing cadence, usually 70 to 90 rpm, matches the speed you can actually sustain on that grade. This table lets you scan every combination at once instead of guessing between chainring and cog changes mid-climb.
Why does the same gear give different speeds for different riders?
Because speed depends on cadence as much as on the gear itself: a rider spinning at 100 rpm goes faster in the same gear than one grinding at 70 rpm. Wheel and tyre size also shift development slightly, which this calculator accounts for through the wheel selection.
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Overload logs cadence and speed per ride
Overload records cadence and speed automatically on every ride, no manual gear tracking required. Free on iOS and Android.