【How-to】How to calculate gear ratio

What Is a Gear Ratio? When you hear people refer to numbers like 3.08, 3.73, or 4.10, they’re talking about the ratio of the ring-and-pinion gears in the rear axle—hence, the numbers are more accurately 3.08:1, 3.73:1, or 4.10:1. … That also means that for every one turn of the ring gear, the pinion will turn 4.11 times.