Gear Ratio Calculator - Calcunation.com Find the output speed and torque of a gear increaser with this Gear Ratio Calculator. A gear reducer increases torque and decreases speed. A gear increaser reduces torque and increases speed. This calculator determines output torque and speed for a speed increaser. Input Torque (in/lbs): Input Speed (RPM): Ratio: :1Fill in input torque, input speed, and ratio to determine output torque and speed.