GlenCalc

Gear ratio calculator

Enter the teeth on the driving (input) gear and the driven (output) gear. Pulleys work the same way with diameters.

Your answer

Gear ratio3 : 1
Output speed600 RPM
Output torque29.4 N·m

Worked out in your browser. Nothing you type is sent to a server.

How we worked it out

Updated as you change the numbers.

  1. Ratio = driven teeth ÷ driving teeth. Output speed = input ÷ ratio. Output torque = input × ratio × efficiency.

Method and assumptions

A larger driven gear slows the output and multiplies torque by the same ratio, less friction losses.

Questions

What is the output speed of a 12:36 tooth reduction at 1,800 RPM?

600 RPM, a 3:1 ratio.

Sources

Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.

Embed this calculator on your site

Free to use. Paste this where you want the calculator; it runs in your visitors’ browsers, sets no cookies and sends nothing to us.

Related calculators