What is the gear ratio equal to?

The gear ratio is the ratio of the number of teeth on two meshing gears or the ratio of their diameters. It determines how the speed and torque are transferred between the gears; a higher gear ratio results in more torque and less speed, while a lower ratio provides higher speed with less torque. Mathematically, it can be expressed as the number of teeth on the driven gear divided by the number of teeth on the driving gear.