How to use it
- Enter driver and driven gear tooth counts.
- Optionally enter input RPM.
- Calculate the ratio, speed direction and ideal output RPM.
Gear Ratio Calculator
Compare driver and driven tooth counts and estimate ideal output speed.
Important: This calculator is for educational and estimation purposes only. It is not machinery operation, safety, engineering, or compliance advice. Always consult qualified professionals for real-world automation or manufacturing decisions.
About the Gear Ratio Calculator
This calculator describes the ideal speed relationship between two meshing gears using tooth counts.
Formula
Gear ratio equals driven teeth divided by driver teeth. Ideal output RPM equals input RPM divided by that ratio.
Example
A 20-tooth driver and 60-tooth driven gear give a 3:1 ratio; 1,200 input RPM becomes 400 ideal output RPM.
Notes
The result excludes losses, backlash, loads, strength, geometry and mechanical design constraints.