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Bicycle Gear Ratio Dynamic Chart

Gear Chart and Calculations

Rhodes Perry
Written by Rhodes Perry
Last updated on April 12th, 2023

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

Should you have any questions or require further clarification on the topic, please feel free to connect with our expert author Rhodes Perry by leaving a comment below. We value your engagement and are here to assist you.

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Rhodes Perry

Rhodes Perry
Rhodes is a writer, social justice advocate, and passionate cyclist. He primarily spends his time in the saddle commuting or riding multi-day, self-supported tours, and volunteers time wrenching at his local bike coop.

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