Bicycle Gear Ratio Chart & Calculator

How to calculate bicycle gear ratio?

Simple, just divide your rear cog size from your front chainring size. If you know their numbers, just input them below and we’ll calculate it automatically for you!

Also take a look at our complete bicycle gear ratio chart below to see how your size compares to other gearing options.

Step 1 - Input your gear information

Front chainring size

Rear cog size

Only input numbers!

Results - Your calculated data will show here!

Gear Ratio: {{ (chainRing / rearCog) | number:2 }}

Gear ratios below 2 are considered small-size gears

Gear ratios between 2 and 3 and considered mid-size gears

Gear ratios greater than 3 are considered large-size gears

Complete Bicycle Gear Ratio Chart

Here is a complete bicycle gear ratio chart of the most commonly used bicycle chainring and cog sizes. Hover over the cells to highlight and see the gearing information.

Teeth	28	29	30	31	32	33	34	35	36	37	38	39	40	41	42	43	44	45	46	47	48	49	50	51	52	53	54	Teeth
10	2.8	2.9	3	3.1	3.2	3.3	3.4	3.5	3.6	3.7	3.8	3.9	4	4.1	4.2	4.3	4.4	4.5	4.6	4.7	4.8	4.9	5	5.1	5.2	5.3	5.4	10
11	2.55	2.64	2.73	2.82	2.91	3	3.09	3.18	3.27	3.36	3.45	3.55	3.64	3.73	3.82	3.91	4	4.09	4.18	4.27	4.36	4.45	4.55	4.64	4.73	4.82	4.91	11
12	2.33	2.42	2.5	2.58	2.67	2.75	2.83	2.92	3	3.08	3.17	3.25	3.33	3.42	3.5	3.58	3.67	3.75	3.83	3.92	4	4.08	4.17	4.25	4.33	4.42	4.5	12
13	2.15	2.23	2.31	2.38	2.46	2.54	2.62	2.69	2.77	2.85	2.92	3	3.08	3.15	3.23	3.31	3.38	3.46	3.54	3.62	3.69	3.77	3.85	3.92	4	4.08	4.15	13
14	2	2.07	2.14	2.21	2.29	2.36	2.43	2.5	2.57	2.64	2.71	2.79	2.86	2.93	3	3.07	3.14	3.21	3.29	3.36	3.43	3.5	3.57	3.64	3.71	3.79	3.86	14
15	1.87	1.93	2	2.07	2.13	2.2	2.27	2.33	2.4	2.47	2.53	2.6	2.67	2.73	2.8	2.87	2.93	3	3.07	3.13	3.2	3.27	3.33	3.4	3.47	3.53	3.6	15
16	1.75	1.81	1.88	1.94	2	2.06	2.13	2.19	2.25	2.31	2.38	2.44	2.5	2.56	2.63	2.69	2.75	2.81	2.88	2.94	3	3.06	3.13	3.19	3.25	3.31	3.38	16
17	1.65	1.71	1.76	1.82	1.88	1.94	2	2.06	2.12	2.18	2.24	2.29	2.35	2.41	2.47	2.53	2.59	2.65	2.71	2.76	2.82	2.88	2.94	3	3.06	3.12	3.18	17
18	1.56	1.61	1.67	1.72	1.78	1.83	1.89	1.94	2	2.06	2.11	2.17	2.22	2.28	2.33	2.39	2.44	2.5	2.56	2.61	2.67	2.72	2.78	2.83	2.89	2.94	3	18
19	1.47	1.53	1.58	1.63	1.68	1.74	1.79	1.84	1.89	1.95	2	2.05	2.11	2.16	2.21	2.26	2.32	2.37	2.42	2.47	2.53	2.58	2.63	2.68	2.74	2.79	2.84	19
20	1.4	1.45	1.5	1.55	1.6	1.65	1.7	1.75	1.8	1.85	1.9	1.95	2	2.05	2.1	2.15	2.2	2.25	2.3	2.35	2.4	2.45	2.5	2.55	2.6	2.65	2.7	20
21	1.33	1.38	1.43	1.48	1.52	1.57	1.62	1.67	1.71	1.76	1.81	1.86	1.9	1.95	2	2.05	2.1	2.14	2.19	2.24	2.29	2.33	2.38	2.43	2.48	2.52	2.57	21
22	1.27	1.32	1.36	1.41	1.45	1.5	1.55	1.59	1.64	1.68	1.73	1.77	1.82	1.86	1.91	1.95	2	2.05	2.09	2.14	2.18	2.23	2.27	2.32	2.36	2.41	2.45	22
23	1.22	1.26	1.3	1.35	1.39	1.43	1.48	1.52	1.57	1.61	1.65	1.7	1.74	1.78	1.83	1.87	1.91	1.96	2	2.04	2.09	2.13	2.17	2.22	2.26	2.3	2.35	23
24	1.17	1.21	1.25	1.29	1.33	1.38	1.42	1.46	1.5	1.54	1.58	1.63	1.67	1.71	1.75	1.79	1.83	1.88	1.92	1.96	2	2.04	2.08	2.13	2.17	2.21	2.25	24
25	1.12	1.16	1.2	1.24	1.28	1.32	1.36	1.4	1.44	1.48	1.52	1.56	1.6	1.64	1.68	1.72	1.76	1.8	1.84	1.88	1.92	1.96	2	2.04	2.08	2.12	2.16	25
26	1.08	1.12	1.15	1.19	1.23	1.27	1.31	1.35	1.38	1.42	1.46	1.5	1.54	1.58	1.62	1.65	1.69	1.73	1.77	1.81	1.85	1.88	1.92	1.96	2	2.04	2.08	26
27	1.04	1.07	1.11	1.15	1.19	1.22	1.26	1.3	1.33	1.37	1.41	1.44	1.48	1.52	1.56	1.59	1.63	1.67	1.7	1.74	1.78	1.81	1.85	1.89	1.93	1.96	2	27
28	1	1.04	1.07	1.11	1.14	1.18	1.21	1.25	1.29	1.32	1.36	1.39	1.43	1.46	1.5	1.54	1.57	1.61	1.64	1.68	1.71	1.75	1.79	1.82	1.86	1.89	1.93	28
29	0.97	1	1.03	1.07	1.1	1.14	1.17	1.21	1.24	1.28	1.31	1.34	1.38	1.41	1.45	1.48	1.52	1.55	1.59	1.62	1.66	1.69	1.72	1.76	1.79	1.83	1.86	29
30	0.93	0.97	1	1.03	1.07	1.1	1.13	1.17	1.2	1.23	1.27	1.3	1.33	1.37	1.4	1.43	1.47	1.5	1.53	1.57	1.6	1.63	1.67	1.7	1.73	1.77	1.8	30
31	0.9	0.94	0.97	1	1.03	1.06	1.1	1.13	1.16	1.19	1.23	1.26	1.29	1.32	1.35	1.39	1.42	1.45	1.48	1.52	1.55	1.58	1.61	1.65	1.68	1.71	1.74	31
32	0.88	0.91	0.94	0.97	1	1.03	1.06	1.09	1.13	1.16	1.19	1.22	1.25	1.28	1.31	1.34	1.38	1.41	1.44	1.47	1.5	1.53	1.56	1.59	1.63	1.66	1.69	32
33	0.85	0.88	0.91	0.94	0.97	1	1.03	1.06	1.09	1.12	1.15	1.18	1.21	1.24	1.27	1.3	1.33	1.36	1.39	1.42	1.45	1.48	1.52	1.55	1.58	1.61	1.64	33