Mechanical / 01
Gear Ratio Calculator
Calculate gear reduction ratio, output speed in rpm, and ideal output torque in N·m.
How it works
ratio = driven teeth / driver teeth; output rpm = input rpm / ratio; output torque = input torque × ratio
A 20-tooth driver and 60-tooth driven gear give 3:1. At 1,500 rpm and 10 N·m input, output is 500 rpm and 30 N·m.
FAQ
Which gear is the driver?
The driver receives power; the driven gear delivers the output.
Does this include efficiency?
No. Torque assumes ideal power transfer without friction or other losses.
What does a ratio below one mean?
The driven gear turns faster than the driver, with lower ideal torque.