Home·Bike gearing

168 bike gears — 50×25 carries you 4.21 m per pedal stroke

Every pairing of 12 chainrings and 14 sprockets, worked out as a ratio and as the distance one pedal stroke carries you. Neither tooth count means anything on its own — the gear is set by the one number you get from dividing them.

One ratio decides everything

A chain does not stretch, so one turn of the chainring turns the sprocket by the ratio of their teeth, and the rear wheel simply follows. Multiply that ratio by the wheel circumference and you have the distance one pedal stroke carries you.

Different teeth, same gear

A 53×19 and a 39×14 share almost the same ratio, so one pedal stroke carries you the same distance despite wholly different tooth counts. That is why "which gear" means something different on every bike, and why the ratio is the only thing you can compare. Each cell lists the other combinations that feel the same.

A big gear is not a fast gear

Speed is the ratio multiplied by cadence. Grinding a big gear slowly and spinning a small one quickly give the same speed, but legs last far longer doing the second — which is why most riders pick the gear that keeps them near 80 to 90 revolutions a minute.

Wheels are taken as 700×25C

Figures use a 2,105 mm circumference. Tyre width and pressure shift that by a few millimetres, but comparing gears only needs one consistent value, so it is fixed. On 650B or 26-inch wheels every distance and speed here shrinks by the same proportion.

At a glance

Gear ratio

34T×17T · 2

34×11
3.0916.506 m
34×12
2.8335.964 m
34×13
2.6155.505 m
34×14
2.4295.112 m
34×15
2.2674.771 m
34×16
2.1254.473 m
34×17
24.21 m
34×19
1.7893.767 m
34×21
1.6193.408 m
34×23
1.4783.112 m
34×25
1.362.863 m
34×28
1.2142.556 m
34×32
1.0632.237 m
34×36
0.9441.988 m

36T×17T · 2.118

36×11
3.2736.889 m
36×12
36.315 m
36×13
2.7695.829 m
36×14
2.5715.413 m
36×15
2.45.052 m
36×16
2.254.736 m
36×17
2.1184.458 m
36×19
1.8953.988 m
36×21
1.7143.609 m
36×23
1.5653.295 m
36×25
1.443.031 m
36×28
1.2862.706 m
36×32
1.1252.368 m
36×36
12.105 m

38T×17T · 2.235

38×11
3.4557.272 m
38×12
3.1676.666 m
38×13
2.9236.153 m
38×14
2.7145.714 m
38×15
2.5335.333 m
38×16
2.3754.999 m
38×17
2.2354.705 m
38×19
24.21 m
38×21
1.813.809 m
38×23
1.6523.478 m
38×25
1.523.2 m
38×28
1.3572.857 m
38×32
1.1882.5 m
38×36
1.0562.222 m

39T×17T · 2.294

39×11
3.5457.463 m
39×12
3.256.841 m
39×13
36.315 m
39×14
2.7865.864 m
39×15
2.65.473 m
39×16
2.4385.131 m
39×17
2.2944.829 m
39×19
2.0534.321 m
39×21
1.8573.909 m
39×23
1.6963.569 m
39×25
1.563.284 m
39×28
1.3932.932 m
39×32
1.2192.565 m
39×36
1.0832.28 m

40T×17T · 2.353

40×11
3.6367.655 m
40×12
3.3337.017 m
40×13
3.0776.477 m
40×14
2.8576.014 m
40×15
2.6675.613 m
40×16
2.55.263 m
40×17
2.3534.953 m
40×19
2.1054.432 m
40×21
1.9054.01 m
40×23
1.7393.661 m
40×25
1.63.368 m
40×28
1.4293.007 m
40×32
1.252.631 m
40×36
1.1112.339 m

42T×17T · 2.471

42×11
3.8188.037 m
42×12
3.57.368 m
42×13
3.2316.801 m
42×14
36.315 m
42×15
2.85.894 m
42×16
2.6255.526 m
42×17
2.4715.201 m
42×19
2.2114.653 m
42×21
24.21 m
42×23
1.8263.844 m
42×25
1.683.536 m
42×28
1.53.158 m
42×32
1.3132.763 m
42×36
1.1672.456 m

44T×17T · 2.588

44×11
48.42 m
44×12
3.6677.718 m
44×13
3.3857.125 m
44×14
3.1436.616 m
44×15
2.9336.175 m
44×16
2.755.789 m
44×17
2.5885.448 m
44×19
2.3164.875 m
44×21
2.0954.41 m
44×23
1.9134.027 m
44×25
1.763.705 m
44×28
1.5713.308 m
44×32
1.3752.894 m
44×36
1.2222.573 m

46T×17T · 2.706

46×11
4.1828.803 m
46×12
3.8338.069 m
46×13
3.5387.448 m
46×14
3.2866.916 m
46×15
3.0676.455 m
46×16
2.8756.052 m
46×17
2.7065.696 m
46×19
2.4215.096 m
46×21
2.194.611 m
46×23
24.21 m
46×25
1.843.873 m
46×28
1.6433.458 m
46×32
1.4383.026 m
46×36
1.2782.69 m

48T×17T · 2.824

48×11
4.3649.185 m
48×12
48.42 m
48×13
3.6927.772 m
48×14
3.4297.217 m
48×15
3.26.736 m
48×16
36.315 m
48×17
2.8245.944 m
48×19
2.5265.318 m
48×21
2.2864.811 m
48×23
2.0874.393 m
48×25
1.924.042 m
48×28
1.7143.609 m
48×32
1.53.158 m
48×36
1.3332.807 m

50T×17T · 2.941

50×11
4.5459.568 m
50×12
4.1678.771 m
50×13
3.8468.096 m
50×14
3.5717.518 m
50×15
3.3337.017 m
50×16
3.1256.578 m
50×17
2.9416.191 m
50×19
2.6325.539 m
50×21
2.3815.012 m
50×23
2.1744.576 m
50×25
24.21 m
50×28
1.7863.759 m
50×32
1.5633.289 m
50×36
1.3892.924 m

52T×17T · 3.059

52×11
4.7279.951 m
52×12
4.3339.122 m
52×13
48.42 m
52×14
3.7147.819 m
52×15
3.4677.297 m
52×16
3.256.841 m
52×17
3.0596.439 m
52×19
2.7375.761 m
52×21
2.4765.212 m
52×23
2.2614.759 m
52×25
2.084.378 m
52×28
1.8573.909 m
52×32
1.6253.421 m
52×36
1.4443.041 m

53T×17T · 3.118

53×11
4.81810.142 m
53×12
4.4179.297 m
53×13
4.0778.582 m
53×14
3.7867.969 m
53×15
3.5337.438 m
53×16
3.3136.973 m
53×17
3.1186.563 m
53×19
2.7895.872 m
53×21
2.5245.313 m
53×23
2.3044.851 m
53×25
2.124.463 m
53×28
1.8933.984 m
53×32
1.6563.486 m
53×36
1.4723.099 m

Worth knowing

  • The ratio is the chainring divided by the sprocket — bigger means harder and further.
  • Two combinations with the same ratio are the same gear, whatever the tooth counts.
  • Speed is ratio times cadence, so neither number settles it alone.
  • These figures assume 700×25C wheels with a 2,105 mm circumference.

Common questions

Q. How is a gear ratio worked out?

Divide the chainring teeth by the sprocket teeth — 50 over 25 is 2.0. Multiply that by the wheel circumference and you get the distance one pedal stroke carries you.

Q. Why not just compare "which gear"?

Because it means something different on every bike. Third gear with one pair of tooth counts is a completely different gear from third with another. The ratio is the only comparable number.

Q. Does a bigger gear make you faster?

Not on its own. Speed is ratio times cadence, so grinding a big gear slowly and spinning a small one quickly give the same speed — and legs hold the second far longer.

Q. What cadence should I aim for?

Around 80 to 90 revolutions a minute for long rides. Below that the load piles onto the knees; above it the breathing gives out first. Pick the gear that keeps you between the two.

Q. What changes with a different wheel size?

Distance and speed scale with the circumference, so both shrink or grow in proportion. The ratio itself has nothing to do with wheels — only the tooth counts set it.