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OO gauge vs O gauge - Which is best choice for you?

Model railway enthusiasts have been debating the relative merits of OO gauge and O gauge for many years.

Both gauges have their pros and cons, and it can be difficult to decide which is the best option for a particular layout.

In this article, we will compare and contrast both OO gauge and O gauge, highlighting the advantages and disadvantages of each model railway gauge.

What size is OO gauge?

OO gauge is the most popular gauge of model railway in the UK.

OO scale models are typically 1:76 in size, making them 4mm to one foot.

This makes the OO gauge slightly smaller than the O gauge

What size is O Gauge

O gauge is a model railway scale that was first introduced in the UK in the 1930s, which is 1:48 or 7mm to one foot.

It is the most popular scale in the world, and many enthusiasts consider it to be the most ideal scale available, allowing high detail, a satisfying size, and small enough for indoor layouts.

Basic comparisons: OO Gauge vs O Gauge


OO Gauge

O Gauge

Cost of 0-6-0 loco



Cost of Tender loco



Cost of a Coach



Cost of a waggon



Cost of 1 yard (936mm) of track



Cost of 1 set of points (turnouts)



Width of track



Length of 0-6-0 loco



Length of Tender loco



The main difference between O gauge and OO gauge is the size of the individual items.

O gauge items are larger than in OO gauge, meaning that a comparable OO layout will be twice as big in O gauge.

It used to be the case that there were more commercially available models with a British outline in OO gauge, which was a major advantage.

However, this is no longer the case.

Manufacturers such as Dapol and Heljan now produce almost as many models in O gauge as they do OO gauge.

OO Gauge benefits

  • Large range of locomotives and rolling stock available off the shelf
  • A six-foot by four-foot board can hold a substantial model railway
  • Lots of designs are available for you to copy or use as inspiration
  • Model buildings are readily available as kits or as decorated resin castings
  • OO gauge model lighting is available
  • There is a buoyant second-hand market

OO Gauge disadvantages

  • Small details on models are easily damaged
  • Best left permanently attached to a baseboard

O Gauge benefits

  • Model locomotives and rolling stock available off the shelf with high levels of detail
  • O Gauge items are generally more robust
  • Easier to include technology like synchronised smoke generators
  • Working locomotive lighting is much more practical
  • Better DCC sound reproduction as larger speakers can be used
  • O gauge railways can be used outdoors
  • Easier to work on and repair models than OO gauge

O Gauge disadvantages

  • It uses twice the amount of space as a OO gauge layout.

Further Reading