When I first looked into the differences between model train gauges and scales I found it quite confusing…I never realised there was so much to it! And I don’t know about you, but I find it hard to visualise the size of something at a scale of 1:76.2!?

For me, knowing the width of the model railway tracks in millimeters at their respective gauges gave a much clearer indication of the size to expect, therefore that’s how I’ve explained them below for you…hope it helps!

What is a Model Train Scale?

The scale, or size, of a model train is proportionally relative to it’s size in real life (the model train is a scaled down version of the real thing).

What is a Model Train Gauge?

The gauge refers to the distance between the rails on the track. The rails of a real railway track are spaced approximately 4ft 8″ (142cm) apart – this measurement is reduced dependent on the scale of your model train and referred to as the gauge.

So, how big are they..?

I found that worldwide model train scales and gauges is quite complex, certainly for model railway beginners. So to simplify, I’ve listed the most common ones below:

  • HO Gauge – Distance between track rails is 16.5mm.
  • OO Gauge – Distance between track rails is 16.5mm, but the model trains themselves are slightly larger than HO Gauge model trains. OO gauge model trains will run on HO gauge railway tracks.
  • N Gauge – Approximately half the size of OO with a distance of 9mm between track rails.

Other model train scales and gauges you may discover include:

  • OO9 – Distance between the track rails is 9mm, same as N gauge but the sleepers are more realistic but have bigger gaps between them
  • TT – Distance between the track rails is 12mm
  • O – Distance between the track rails is 32mm
  • Gauge 1 – Distance between the track rails is 45mm
  • Gauge 3 – Distance between track rails is 64mm
  • Ride-On – The big one! Distance between rails either 127mm or 184mm (not one for the front room!)

Photo by Brett Sayles