Bicycle gear calculator

Chainring and cog plus wheel size gives gear inches, meters of development, and speed at a cadence.

Calculated in this browser. Nothing is sent anywhere.

Teeth 5–120, wheel 200–1000 mm, crank 100–200 mm, cadence 20–200 rpm.

How to use

  1. Enter chainring teeth, cog teeth, and wheel diameter.
  2. Read gear inches and development.
  3. Optionally set a cadence for the speed.

What it supports

Chainring and cog 5–120 teeth each, wheel 200–1,000 mm outer diameter (about 680–700 mm for a 700c road tire), crank 100–200 mm for the gain ratio, cadence 20–200 rpm. Tire width changes the true diameter — measure for precision.

Related tools

Related guides