Transmission Ratio

The transmission ratio is the relationship of the amount of gear-teeth, the diameter and the torque from the driven- to the driving wheels. The RPM is exactly the opposite.
The overall transmission ratio is created by multiplying the individual ratios.

Ratio from the number of teeth        z2 i =        z1 z2 = z1 · i          z2 z1 =         i

Ratio from diameters
d2 i =        d1	d2 = d1 · i	d2 d1 =         i

Ratio from rotary speeds
n1 i =        n2	n1 = n2 · i	n1 n2 =          i

Overall ratio in general
iges = i1 · i2 · i3	iges i1 =         i2 · i3

Overall ratio from the number of teeth, diameters
z2·z4·z6 iges =            z1·z3·z5	d2·d4·d6 iges =            d1·d3·d5

Overall ratio from torques
ME iges =           MA	ME = MA · iges	ME MA =           iges

Overall ratio from rotary speeds
nA iges =           nE	nA = nE·iges	nA nE =             iges