In Model Railroading, What is The Difference Between Gauge and Scale?
Most people don’t know there is a difference between the scale of a model train and the gauge of a model train. No, they are not the same. If someone is talking about a Model Railways OO-Gauge engine, they are referring to an engine that runs on a double zero gauge track. Double zero gauge track is 16.5 mm. Gauge is the measurement between the rails of the track.
The scale is the size of the model train compared to the same train in full size. So if you use a 1:76 scale, each measurement on the model would be multiplied by 76 to get the measurement of the life-size version.