Gear Ratio Calculator

Calculate gear ratios, output speed, and output torque with an animated gear pair

Gear ratio
3.000 : 1
Output RPM
40.00
Output torque
30.00 N·m
Type
Reduction

Gear ratio fundamentals

The ratio equals driven teeth ÷ driver teeth. A reduction (ratio > 1) trades speed for torque: output RPM is divided by the ratio while ideal output torque is multiplied by it (ignoring friction losses). The animation shows relative rotation speeds and directions — the driven gear turns opposite to the driver in a simple external pair.

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