Gear calculator.
Chainring, cog and cadence in. Ratio, rollout, gear inches and speed out.
Pick a chainring and cog, set your cadence, and see what that gear gives you. The table lists every combination from 46–55T by 13–17T at the same cadence, so you can compare gears before race night. Figures assume a 700c wheel with a 23mm tire (2.096 m rollout per wheel revolution).
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Chainring
Cog
- Gear ratio
- 3.33
- Rollout
- 6.99m
- Gear inches
- 87.6in
- Speed
- 37.7km/h
- Ratio
- 50 ÷ 15 = 3.33
- Rollout
- 3.33 × 2.096 m = 6.99 m
- Gear inches
- 3.33 × 26.3 in = 87.6 in
- Speed
- 6.99 m × 90 rpm × 60 ÷ 1000 = 37.7 km/h
| Chainring | Cog | Ratio | Gear inches | Rollout (m) | Speed at 90 rpm (km/h) |
|---|---|---|---|---|---|
| 17T | 2.71 | 71.1 | 5.67 | 30.6 | |
| 17T | 2.76 | 72.6 | 5.79 | 31.3 | |
| 17T | 2.82 | 74.2 | 5.92 | 32.0 | |
| 16T | 2.88 | 75.5 | 6.03 | 32.5 | |
| 17T | 2.88 | 75.7 | 6.04 | 32.6 | |
| 16T | 2.94 | 77.2 | 6.16 | 33.2 | |
| 17T | 2.94 | 77.3 | 6.16 | 33.3 | |
| 16T | 3.00 | 78.8 | 6.29 | 34.0 | |
| 17T | 3.00 | 78.8 | 6.29 | 34.0 | |
| 17T | 3.06 | 80.3 | 6.41 | 34.6 | |
| 16T | 3.06 | 80.4 | 6.42 | 34.7 | |
| 15T | 3.07 | 80.6 | 6.43 | 34.7 | |
| 17T | 3.12 | 81.9 | 6.53 | 35.3 | |
| 16T | 3.13 | 82.1 | 6.55 | 35.4 | |
| 15T | 3.13 | 82.3 | 6.57 | 35.5 | |
| 17T | 3.18 | 83.4 | 6.66 | 36.0 | |
| 16T | 3.19 | 83.7 | 6.68 | 36.1 | |
| 15T | 3.20 | 84.1 | 6.71 | 36.2 | |
| 17T | 3.24 | 85.0 | 6.78 | 36.6 | |
| 16T | 3.25 | 85.4 | 6.81 | 36.8 | |
| 15T | 3.27 | 85.8 | 6.85 | 37.0 | |
| 14T | 3.29 | 86.3 | 6.89 | 37.2 | |
| 16T | 3.31 | 87.0 | 6.94 | 37.5 | |
| 15T | 3.33 | 87.6 | 6.99 | 37.7 | |
| 14T | 3.36 | 88.2 | 7.04 | 38.0 | |
| 16T | 3.38 | 88.7 | 7.07 | 38.2 | |
| 15T | 3.40 | 89.3 | 7.13 | 38.5 | |
| 14T | 3.43 | 90.1 | 7.19 | 38.8 | |
| 16T | 3.44 | 90.3 | 7.21 | 38.9 | |
| 15T | 3.47 | 91.1 | 7.27 | 39.2 | |
| 14T | 3.50 | 91.9 | 7.34 | 39.6 | |
| 15T | 3.53 | 92.8 | 7.41 | 40.0 | |
| 13T | 3.54 | 92.9 | 7.42 | 40.0 | |
| 14T | 3.57 | 93.8 | 7.49 | 40.4 | |
| 15T | 3.60 | 94.6 | 7.55 | 40.7 | |
| 13T | 3.62 | 95.0 | 7.58 | 40.9 | |
| 14T | 3.64 | 95.7 | 7.64 | 41.2 | |
| 15T | 3.67 | 96.3 | 7.69 | 41.5 | |
| 13T | 3.69 | 97.0 | 7.74 | 41.8 | |
| 14T | 3.71 | 97.6 | 7.79 | 42.0 | |
| 13T | 3.77 | 99.0 | 7.90 | 42.7 | |
| 14T | 3.79 | 99.4 | 7.93 | 42.8 | |
| 13T | 3.85 | 101.0 | 8.06 | 43.5 | |
| 14T | 3.86 | 101.3 | 8.08 | 43.7 | |
| 13T | 3.92 | 103.0 | 8.22 | 44.4 | |
| 14T | 3.93 | 103.2 | 8.23 | 44.5 | |
| 13T | 4.00 | 105.1 | 8.38 | 45.3 | |
| 13T | 4.08 | 107.1 | 8.55 | 46.1 | |
| 13T | 4.15 | 109.1 | 8.71 | 47.0 | |
| 13T | 4.23 | 111.1 | 8.87 | 47.9 |