What are the Model Train Scales

There are many different scales or gauges of Model Trains. They all have their pros and cons.  There are 2 main differences.  The first and most obvious would be the size or ratio of difference between the real life train and its model.  An HO scale locomotive is 87 times smaller than its real life counterpart or said conversely the real life steam locomotive is 87 times bigger than its HO scale model.  The second main difference would be availability of product sold commercially.  The more product out there on the market the less expensive the hobby overall could be. The more product available the less you have to scratch build from raw materials etc, etc.

Today's most popular model train scales. There are others but these are the heavy hitters.

Name    Size
G Scale  1:32
O Scale  1:48
On30 Scale 1:48 (O Scale running on HO track)
S Scale   1:64
HO Scale  1:87
N Scale 1:148
Z Scale 1:220