CalculatorsBicycle Gear Ratio Calculator

Bicycle Gear Ratio Calculator

Divide chainring teeth by cog teeth. A 52×11 is about 4.72; a 36×34 is about 1.05. Lower is easier to spin uphill. The pair pages below run every tooth on a catalogued chainring against every cog on a catalogued cassette.

Inputs

Chainring teethCog teeth

Results

Gear ratio: 4.72

How the number is made

Ratio = chainring ÷ cog. Published figures are truncated to two decimal places, so 36 ÷ 34 is shown as 1.05 and 52 ÷ 11 as 4.72. The live form uses the same truncation.

Ratio ignores wheel size. Gear inches and rollout add the tyre.

Gear ratio. Truncated to two decimal places.

How pair pages are chosen

A chainring is paired with a cassette only when the cassette speed is in the chainring’s compatible-speed list. A track ring and a 12-speed cassette are not given a URL.

Related calculators

Gear Inches and Roll-out Calculator
Same teeth, different development once the wheel size is in the sum.
Cadence to Speed Calculator
Turns this ratio into km/h at the cadence you actually hold.
Cassette Range Calculator
The percent range is the cassette alone, before a chainring is chosen.

Chainring and cassette pairs

Shimano Ultegra R8100 52-36

SRAM Red AXS 48-35

Shimano GRX RX810 48-31

Shimano 105 R7000 11-32T0.96–4.36 · mullet · HG

SRAM Force 1 40

Shimano Deore XT M8100 34

SRAM XX1 Eagle 32

Campagnolo Super Record Wireless 50-34

Questions

What is a climbing ratio?

Around 1.0 or below (for example 36÷34 or 34÷51) lets you spin a steep grade. Above 1.5, the easiest gear is already hard work.

Why truncate to 1.05 instead of rounding to 1.06?

36÷34 is 1.0588. This site truncates to two decimals so every pair page quotes the same published figure.

Does the chainring brand change the ratio?

No. Teeth do. Brand, speeds and freehub decide whether the pair can be built.

Related gear

Replacement cassette
Match the freehub (HG, Micro Spline, XD, XDR) before the tooth count.
$40–$400
Matching chain
Speed count of the chain has to match the cassette, not just the chainring brand.
$20–$80

Disclaimer — no professional advice, no liability

These calculators are simplified estimates for education. They are not a bike fit, a structural inspection, or a torque specification that overrides the number printed on a part. Confirm chain length, spoke length, tire fit and bolt torque on the bicycle before you ride.

These calculators, pages and any related content are provided “as is” and “as available”, solely for general educational and informational purposes. They are simplified mathematical estimates, not a professional bike fit, a structural inspection, a manufacturer torque specification or a training, nutrition or medical plan.

Results can be wrong, incomplete or inapplicable to your frame, wheels, tires, drivetrain or suspension. You must independently verify every figure, assume all risk, and confirm chain length before you cut, spoke length before you lace, tire and rim compatibility before you inflate, and the torque printed on the part before you tighten it.

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