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Compare your bike gearing.

Changing your cassette or chainring? See what you gain on the climbs and how your top gear changes.

A Current setup

Start with an example

Chainring teeth

One to three rings, e.g. 50 / 34 or 40.

Where do I find this?

Crank with two chainrings. The big ring is marked 50T, the small ring 34T.

Chainrings are the toothed rings at the front, on the crank. The tooth count is usually stamped on the ring itself, for example “50T” or “34T”, sometimes among other codes.

“50/34” means two chainrings: a big ring with 50 teeth and a small ring with 34. “40” means one chainring with 40 teeth (1×).

Cassette example

Examples only, not a verified match for your cassette. Cassettes with the same range can have different steps.

Sprocket teeth

List every sprocket, separated by commas, not just the range.

Where do I find this?

Cassette seen from the side: the smallest sprocket has 11 teeth, the largest 34. Each sprocket is marked with its tooth count.

Sprockets are the toothed rings on the rear wheel; together they form the cassette. The tooth count is often marked on each sprocket, and the range on the cassette or its packaging.

“11–34” gives only the smallest (11) and largest (34) sprocket, not the ones in between.

Find the complete sequence in the specifications for your exact cassette model, using the model code on the cassette and the manufacturer’s documentation. Or count the teeth on each sprocket.

The smallest and largest sprocket are enough for your lowest and highest gear. The gaps between gears need every sprocket.

Rear wheel

Tire width (mm)

Measured wheel circumference

Rollout (mm, optional)

For greater accuracy, measure one full wheel turn with the rider on the bike. Leave blank to estimate from tire size.

B Compare with

Start with an example

Chainring teeth

One to three rings, e.g. 50 / 34 or 40.

Where do I find this?

Crank with two chainrings. The big ring is marked 50T, the small ring 34T.

Chainrings are the toothed rings at the front, on the crank. The tooth count is usually stamped on the ring itself, for example “50T” or “34T”, sometimes among other codes.

“50/34” means two chainrings: a big ring with 50 teeth and a small ring with 34. “40” means one chainring with 40 teeth (1×).

Cassette example

Examples only, not a verified match for your cassette. Cassettes with the same range can have different steps.

Sprocket teeth

List every sprocket, separated by commas, not just the range.

Where do I find this?

Cassette seen from the side: the smallest sprocket has 11 teeth, the largest 34. Each sprocket is marked with its tooth count.

Sprockets are the toothed rings on the rear wheel; together they form the cassette. The tooth count is often marked on each sprocket, and the range on the cassette or its packaging.

“11–34” gives only the smallest (11) and largest (34) sprocket, not the ones in between.

Find the complete sequence in the specifications for your exact cassette model, using the model code on the cassette and the manufacturer’s documentation. Or count the teeth on each sprocket.

The smallest and largest sprocket are enough for your lowest and highest gear. The gaps between gears need every sprocket.

Rear wheel

Tire width (mm)

Measured wheel circumference

Rollout (mm, optional)

For greater accuracy, measure one full wheel turn with the rider on the bike. Leave blank to estimate from tire size.

Cadence (rpm)

Pedal revolutions per minute. Applies to both setups.

Speed units

A Current setup

Lowest ratio
Highest ratio
Total range
Speed at 90 rpm

B Compare with

Lowest ratio
Highest ratio
Total range
Speed at 90 rpm

What this means for climbing

Lower pedal force comes with a higher cadence: you turn the pedals faster, with less force on each revolution. The climb does not take less work. Assumes the same total weight, crank length and drivetrain efficiency, and both setups’ wheel circumference.

What this means for speed

This is gearing potential, not a predicted maximum speed. Your power, the slope, wind and rolling resistance determine the speed you can sustain.

Gaps between gears

A Largest step

B Largest step

More range from the same number of sprockets means bigger steps. Smaller steps keep your cadence steadier when you shift, but leave less range between your lowest and highest gear. Calculated on the same chainring, using every sprocket you entered.

Every gear, on the same scale

Each dot is a gear at your chosen cadence. Further left is lower gearing; further right is higher speed.

Hover, focus or tap a gear for details. Use arrow keys to move between gears.

See all gear combinations

A · Current setup
Ring / sprocket	Ratio	Meters / pedal turn	Gear inches	Speed

B · Compare with
Ring / sprocket	Ratio	Meters / pedal turn	Gear inches	Speed

Calculated speed assumes your chosen cadence, not your available power. This tool compares gearing; it does not check derailleur, chain or freehub compatibility. All ring/sprocket combinations are shown, including cross-chained combinations. Wheel circumference is estimated from tire size unless you enter a measured rollout.

What the numbers mean

Gear ratio: Chainring teeth divided by sprocket teeth. A 34-tooth ring with a 34-tooth sprocket gives a 1:1 ratio.
Range: Highest ratio divided by lowest ratio, multiplied by 100. A 500% range means the top ratio is five times the bottom ratio.
Speed and wheel size: Distance per pedal turn is wheel circumference × gear ratio. Speed in km/h is that distance in meters × cadence × 0.06. Estimated circumference is π × (rim bead-seat diameter + 2 × tire width).
Comparing two bikes: Percentage changes compare distance per pedal turn, so wheel size counts too. Gear inches express the same gearing as an equivalent wheel diameter in inches.

Further reading: Sheldon Brown’s guide to bicycle gearing ↗

Bike gearing questions

Will an 11–34 cassette make climbing easier than an 11–28?

With the same chainrings and wheels, the largest sprocket changes from 28 to 34 teeth. Your bottom gear becomes about 17.6% lower, while your top gear stays the same. Check drivetrain compatibility before changing parts.

Can I compare a 1× drivetrain with a 2× or 3×?

Yes. Enter one, two or three chainrings and list every sprocket. The chart and table show all combinations, including overlapping ratios. This calculator supports derailleur and single-speed setups, not internal-gear hubs.

Does a higher top gear mean I will ride faster?

It means you travel further per pedal revolution. Whether you can sustain that speed depends on power, gradient, wind and rolling resistance. The speeds shown are calculated from cadence, not a performance prediction.

Know your bike. Keep it ready.

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