1. i=n1/n2=D2/D1 ,i=n1/n2=z2/z1.
i represents transmission ratio or gear ratio
n1 represents the speed of drive gear
n2 represents the speed of driven gear
D2 represents the diameter of driven gear
D1 represents the diameter of driving gear
Z2 represents the tooth number of driven gear
Z1 represents the tooth number of driving gear
2.Multistage gear transmission : the transmission ratio between each two shafts is calculated according to the above formula 2: the total transmission ratio from the first axis to the n-axis is calculated according to the following formula: total transmission ratio = (Z2/Z1)×(Z4/Z3)×(Z6/Z5) = (n1/n2)×(n3/n4)×(n5/n6).