Bike gear calculator

Enter chainrings, cogs and wheel: for every combination you get metres per pedal stroke and speed at your chosen cadence.

Chainrings (teeth)

Cassette cogs

Wheel

Cadence (rpm)

What rollout is

It's how many metres you travel with one full pedal revolution: wheel circumference × chainring teeth ÷ cog teeth. A 50×11 on road wheels covers almost 9.6 m per stroke; a 34×28 about 2.6: that's your gearing range.

Comparing cassettes

Before buying a new cassette (or going 1×), compare ranges: do you need more climbing ease (shorter lowest gear) or more top-end (longer highest)? Also check the jumps between adjacent cogs: small jumps = always the right cadence.

Cadence

Speed is rollout × cadence: at 90 rpm each metre of rollout is worth 5.4 km/h. Trained cyclists pedal at 80-100 rpm; grinding below 70 on long climbs taxes muscles more than lungs.