The calculations below are approximate for 700c & 27 Inch wheels.
To calculate the exact gearing, divide the number of chainring teeth by the number of sprocket teeth and multiply the answer by the actual rolling diameter of the tyred wheel. (Divide actual rolling circumference by 3.142 to calculate rolling diameter)
| Sprocket | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 38 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chainring | |||||||||||||||||||||||||
| 20 | 49.1 | 45 | 41.5 | 38.6 | 36 | 33.8 | 31.8 | 30 | 28.4 | 27 | 25.7 | 24.5 | 23.5 | 22.5 | 21.6 | 20.8 | 20 | 19.3 | 18.6 | 18 | 17.4 | 16.9 | 16.4 | 15.9 | 14.2 |
| 21 | 51.5 | 47.3 | 43.6 | 40.5 | 37.8 | 35.4 | 33.4 | 31.5 | 29.8 | 28.4 | 27 | 25.8 | 24.7 | 23.6 | 22.7 | 21.8 | 21 | 20.3 | 19.6 | 18.9 | 18.3 | 17.7 | 17.2 | 16.7 | 14.9 |
| 22 | 54 | 49.5 | 45.7 | 42.4 | 39.6 | 37.1 | 34.9 | 33 | 31.3 | 29.7 | 28.3 | 27 | 25.8 | 24.8 | 23.8 | 22.8 | 22 | 21.2 | 20.5 | 19.8 | 19.2 | 18.6 | 18 | 17.5 | 15.6 |
| 23 | 56.5 | 51.8 | 47.8 | 44.4 | 41.4 | 38.8 | 36.5 | 34.5 | 32.7 | 31.1 | 29.6 | 28.2 | 27 | 25.9 | 24.8 | 23.9 | 23 | 22.2 | 21.4 | 20.7 | 20 | 19.4 | 18.8 | 18.3 | 16.3 |
| 24 | 58.9 | 54 | 49.8 | 46.3 | 43.2 | 40.5 | 38.1 | 36 | 34.1 | 32.4 | 30.9 | 29.5 | 28.2 | 27 | 25.9 | 24.9 | 24 | 23.1 | 22.3 | 21.6 | 20.9 | 20.3 | 19.6 | 19.1 | 17.1 |
| 25 | 61.4 | 56.3 | 51.9 | 48.2 | 45 | 42.2 | 39.7 | 37.5 | 35.5 | 33.8 | 32.1 | 30.7 | 29.3 | 28.1 | 27 | 26 | 25 | 24.1 | 23.3 | 22.5 | 21.8 | 21.1 | 20.5 | 19.9 | 17.8 |
| 26 | 63.8 | 58.5 | 54 | 50.1 | 46.8 | 43.9 | 41.3 | 39 | 36.9 | 35.1 | 33.4 | 31.9 | 30.5 | 29.3 | 28.1 | 27 | 26 | 25.1 | 24.2 | 23.4 | 22.6 | 21.9 | 21.3 | 20.6 | 18.5 |
| 27 | 66.3 | 60.8 | 56.1 | 52.1 | 48.6 | 45.6 | 42.9 | 40.5 | 38.4 | 36.5 | 34.7 | 33.1 | 31.7 | 30.4 | 29.2 | 28 | 27 | 26 | 25.1 | 24.3 | 23.5 | 22.8 | 22.1 | 21.4 | 19.2 |
| 28 | 68.7 | 63 | 58.2 | 54 | 50.4 | 47.3 | 44.5 | 42 | 39.8 | 37.8 | 36 | 34.4 | 32.9 | 31.5 | 30.2 | 29.1 | 28 | 27 | 26.1 | 25.2 | 24.4 | 23.6 | 22.9 | 22.2 | 19.9 |
| 29 | 71.2 | 65.3 | 60.2 | 55.9 | 52.2 | 48.9 | 46.1 | 43.5 | 41.2 | 39.2 | 37.3 | 35.6 | 34 | 32.6 | 31.3 | 30.1 | 29 | 28 | 27 | 26.1 | 25.3 | 24.5 | 23.7 | 23 | 20.6 |
| 30 | 73.6 | 67.5 | 62.3 | 57.9 | 54 | 50.6 | 47.6 | 45 | 42.6 | 40.5 | 38.6 | 36.8 | 35.2 | 33.8 | 32.4 | 31.2 | 30 | 28.9 | 27.9 | 27 | 26.1 | 25.3 | 24.5 | 23.8 | 21.3 |
| 31 | 76.1 | 69.8 | 64.4 | 59.8 | 55.8 | 52.3 | 49.2 | 46.5 | 44.1 | 41.9 | 39.9 | 38 | 36.4 | 34.9 | 33.5 | 32.2 | 31 | 29.9 | 28.9 | 27.9 | 27 | 26.2 | 25.4 | 24.6 | 22 |
| 32 | 78.5 | 72 | 66.5 | 61.7 | 57.6 | 54 | 50.8 | 48 | 45.5 | 43.2 | 41.1 | 39.3 | 37.6 | 36 | 34.6 | 33.2 | 32 | 30.9 | 29.8 | 28.8 | 27.9 | 27 | 26.2 | 25.4 | 22.7 |
| 33 | 81 | 74.3 | 68.5 | 63.6 | 59.4 | 55.7 | 52.4 | 49.5 | 46.9 | 44.6 | 42.4 | 40.5 | 38.7 | 37.1 | 35.6 | 34.3 | 33 | 31.8 | 30.7 | 29.7 | 28.7 | 27.8 | 27 | 26.2 | 23.4 |
| 34 | 83.5 | 76.5 | 70.6 | 65.6 | 61.2 | 57.4 | 54 | 51 | 48.3 | 45.9 | 43.7 | 41.7 | 39.9 | 38.3 | 36.7 | 35.3 | 34 | 32.8 | 31.7 | 30.6 | 29.6 | 28.7 | 27.8 | 27 | 24.2 |
| 35 | 85.9 | 78.8 | 72.7 | 67.5 | 63 | 59.1 | 55.6 | 52.5 | 49.7 | 47.3 | 45 | 43 | 41.1 | 39.4 | 37.8 | 36.3 | 35 | 33.8 | 32.6 | 31.5 | 30.5 | 29.5 | 28.6 | 27.8 | 24.9 |
| 36 | 88.4 | 81 | 74.8 | 69.4 | 64.8 | 60.8 | 57.2 | 54 | 51.2 | 48.6 | 46.3 | 44.2 | 42.3 | 40.5 | 38.9 | 37.4 | 36 | 34.7 | 33.5 | 32.4 | 31.4 | 30.4 | 29.5 | 28.6 | 25.6 |
| 37 | 90.8 | 83.3 | 76.8 | 71.4 | 66.6 | 62.4 | 58.8 | 55.5 | 52.6 | 50 | 47.6 | 45.4 | 43.4 | 41.6 | 40 | 38.4 | 37 | 35.7 | 34.4 | 33.3 | 32.2 | 31.2 | 30.3 | 29.4 | 26.3 |
| 38 | 93.3 | 85.5 | 78.9 | 73.3 | 68.4 | 64.1 | 60.4 | 57 | 54 | 51.3 | 48.9 | 46.6 | 44.6 | 42.8 | 41 | 39.5 | 38 | 36.6 | 35.4 | 34.2 | 33.1 | 32.1 | 31.1 | 30.2 | 27 |
| 39 | 95.7 | 87.8 | 81 | 75.2 | 70.2 | 65.8 | 61.9 | 58.5 | 55.4 | 52.7 | 50.1 | 47.9 | 45.8 | 43.9 | 42.1 | 40.5 | 39 | 37.6 | 36.3 | 35.1 | 34 | 32.9 | 31.9 | 31 | 27.7 |
| 40 | 98.2 | 90 | 83.1 | 77.1 | 72 | 67.5 | 63.5 | 60 | 56.8 | 54 | 51.4 | 49.1 | 47 | 45 | 43.2 | 41.5 | 40 | 38.6 | 37.2 | 36 | 34.8 | 33.8 | 32.7 | 31.8 | 28.4 |
| 41 | 100.6 | 92.3 | 85.2 | 79.1 | 73.8 | 69.2 | 65.1 | 61.5 | 58.3 | 55.4 | 52.7 | 50.3 | 48.1 | 46.1 | 44.3 | 42.6 | 41 | 39.5 | 38.2 | 36.9 | 35.7 | 34.6 | 33.5 | 32.6 | 29.1 |
| 42 | 103.1 | 94.5 | 87.2 | 81 | 75.6 | 70.9 | 66.7 | 63 | 59.7 | 56.7 | 54 | 51.5 | 49.3 | 47.3 | 45.4 | 43.6 | 42 | 40.5 | 39.1 | 37.8 | 36.6 | 35.4 | 34.4 | 33.4 | 29.8 |
| 43 | 105.5 | 96.8 | 89.3 | 82.9 | 77.4 | 72.6 | 68.3 | 64.5 | 61.1 | 58.1 | 55.3 | 52.8 | 50.5 | 48.4 | 46.4 | 44.7 | 43 | 41.5 | 40 | 38.7 | 37.5 | 36.3 | 35.2 | 34.1 | 30.6 |
| 44 | 108 | 99 | 91.4 | 84.9 | 79.2 | 74.3 | 69.9 | 66 | 62.5 | 59.4 | 56.6 | 54 | 51.7 | 49.5 | 47.5 | 45.7 | 44 | 42.4 | 41 | 39.6 | 38.3 | 37.1 | 36 | 34.9 | 31.3 |
| 45 | 110.5 | 101.3 | 93.5 | 86.8 | 81 | 75.9 | 71.5 | 67.5 | 63.9 | 60.8 | 57.9 | 55.2 | 52.8 | 50.6 | 48.6 | 46.7 | 45 | 43.4 | 41.9 | 40.5 | 39.2 | 38 | 36.8 | 35.7 | 32 |
| 46 | 112.9 | 103.5 | 95.5 | 88.7 | 82.8 | 77.6 | 73.1 | 69 | 65.4 | 62.1 | 59.1 | 56.5 | 54 | 51.8 | 49.7 | 47.8 | 46 | 44.4 | 42.8 | 41.4 | 40.1 | 38.8 | 37.6 | 36.5 | 32.7 |
| 47 | 115.4 | 105.8 | 97.6 | 90.6 | 84.6 | 79.3 | 74.6 | 70.5 | 66.8 | 63.5 | 60.4 | 57.7 | 55.2 | 52.9 | 50.8 | 48.8 | 47 | 45.3 | 43.8 | 42.3 | 40.9 | 39.7 | 38.5 | 37.3 | 33.4 |
| 48 | 117.8 | 108 | 99.7 | 92.6 | 86.4 | 81 | 76.2 | 72 | 68.2 | 64.8 | 61.7 | 58.9 | 56.3 | 54 | 51.8 | 49.8 | 48 | 46.3 | 44.7 | 43.2 | 41.8 | 40.5 | 39.3 | 38.1 | 34.1 |
| 49 | 120.3 | 110.3 | 101.8 | 94.5 | 88.2 | 82.7 | 77.8 | 73.5 | 69.6 | 66.2 | 63 | 60.1 | 57.5 | 55.1 | 52.9 | 50.9 | 49 | 47.3 | 45.6 | 44.1 | 42.7 | 41.3 | 40.1 | 38.9 | 34.8 |
| 50 | 122.7 | 112.5 | 103.8 | 96.4 | 90 | 84.4 | 79.4 | 75 | 71.1 | 67.5 | 64.3 | 61.4 | 58.7 | 56.3 | 54 | 51.9 | 50 | 48.2 | 46.6 | 45 | 43.5 | 42.2 | 40.9 | 39.7 | 35.5 |
| 51 | 125.2 | 114.8 | 105.9 | 98.4 | 91.8 | 86.1 | 81 | 76.5 | 72.5 | 68.9 | 65.6 | 62.6 | 59.9 | 57.4 | 55.1 | 53 | 51 | 49.2 | 47.5 | 45.9 | 44.4 | 43 | 41.7 | 40.5 | 36.2 |
| 52 | 127.6 | 117 | 108 | 100.3 | 93.6 | 87.8 | 82.6 | 78 | 73.9 | 70.2 | 66.9 | 63.8 | 61 | 58.5 | 56.2 | 54 | 52 | 50.1 | 48.4 | 46.8 | 45.3 | 43.9 | 42.5 | 41.3 | 36.9 |
| 53 | 130.1 | 119.3 | 110.1 | 102.2 | 95.4 | 89.4 | 84.2 | 79.5 | 75.3 | 71.6 | 68.1 | 65 | 62.2 | 59.6 | 57.2 | 55 | 53 | 51.1 | 49.3 | 47.7 | 46.2 | 44.7 | 43.4 | 42.1 | 37.7 |
| 54 | 132.5 | 121.5 | 112.2 | 104.1 | 97.2 | 91.1 | 85.8 | 81 | 76.7 | 72.9 | 69.4 | 66.3 | 63.4 | 60.8 | 58.3 | 56.1 | 54 | 52.1 | 50.3 | 48.6 | 47 | 45.6 | 44.2 | 42.9 | 38.4 |
| 55 | 135 | 123.8 | 114.2 | 106.1 | 99 | 92.8 | 87.4 | 82.5 | 78.2 | 74.3 | 70.7 | 67.5 | 64.6 | 61.9 | 59.4 | 57.1 | 55 | 53 | 51.2 | 49.5 | 47.9 | 46.4 | 45 | 43.7 | 39.1 |
| 56 | 137.5 | 126 | 116.3 | 108 | 100.8 | 94.5 | 88.9 | 84 | 79.6 | 75.6 | 72 | 68.7 | 65.7 | 63 | 60.5 | 58.2 | 56 | 54 | 52.1 | 50.4 | 48.8 | 47.3 | 45.8 | 44.5 | 39.8 |
| 57 | 139.9 | 128.3 | 118.4 | 109.9 | 102.6 | 96.2 | 90.5 | 85.5 | 81 | 77 | 73.3 | 70 | 66.9 | 64.1 | 61.6 | 59.2 | 57 | 55 | 53.1 | 51.3 | 49.6 | 48.1 | 46.6 | 45.3 | 40.5 |
| 58 | 142.4 | 130.5 | 120.5 | 111.9 | 104.4 | 97.9 | 92.1 | 87 | 82.4 | 78.3 | 74.6 | 71.2 | 68.1 | 65.3 | 62.6 | 60.2 | 58 | 55.9 | 54 | 52.2 | 50.5 | 48.9 | 47.5 | 46.1 | 41.2 |
| 59 | 144.8 | 132.8 | 122.5 | 113.8 | 106.2 | 99.6 | 93.7 | 88.5 | 83.8 | 79.7 | 75.9 | 72.4 | 69.3 | 66.4 | 63.7 | 61.3 | 59 | 56.9 | 54.9 | 53.1 | 51.4 | 49.8 | 48.3 | 46.9 | 41.9 |
| 60 | 147.3 | 135 | 124.6 | 115.7 | 108 | 101.3 | 95.3 | 90 | 85.3 | 81 | 77.1 | 73.6 | 70.4 | 67.5 | 64.8 | 62.3 | 60 | 57.9 | 55.9 | 54 | 52.3 | 50.6 | 49.1 | 47.6 | 42.6 |
