Gear Ratio Calculator

A simple gear ratio calculator to find the speed and mechanical advantage of a gear system of spur gears. Gear ratio is determined solely by the number of teeth on each gear. Check the box if the gear is on the same shaft as the gear above it, leave it unchecked if the gear meshes with the gear above it..

An example gear-train is shown below: The Input Gear meshes with Gear 2. Gear 3 is on the same shaft as Gear 2, and meshes with Gear 4. Gear 5 is on the same shaft as Gear 4, and meshes with Gear 6. The "same shaft" boxes would be checked on Gears 3 and 5 only.

Example Gear Train