Model Train Scales Explained

Model Train Scales Explained

The pros and cons of the various model train scales and how to determine which one is right for you.

If you’re considering building a model railroad, you may be looking to have model train scales explained. There are a few factors that will play a part in picking the right scale for your wants and needs, so it’s a good idea to give some thought to what you’re hoping to get from your train set before you decide on one. For a good visual introduction to the world of model railroad scales, take a look at this brief YouTube video.

How Much Room Do You Have?

First of all, think about how much space you have to work with. If your model train will be going into a smaller area, you’ll definitely want to look at smaller micro scale trains for a smoother and better-looking operation. If you’re a model railroad hobbyist with plenty of room, remember that trains on a larger scale can offer a more detailed and realistic appearance than small scales will.

Look at the minimum curve for each scale in order to see how much room you really have to work with. This is the smallest curve that a train can make without a derailment, so it’s an important part of determining which scale will actually function well within a given space. This article offers up a great explanation of how to determine the minimum curve radius and a rundown of the minimum curves for all of the most common model railroad scales.

What’s Your Budget?

While it’s certainly fun to fantasize about creating an elaborate model train setup, the cost of putting one together might come as a surprise. Keep in mind that the more common the scale, the more equipment and accessories you’ll be able to find, which can also drive the price down. Also, larger components will generally cost more than smaller ones, simply because they use more materials and are more expensive to ship. You’ll definitely want to take a look at supplies for a few different scales in order to compare prices and see what is realistically within your budget. If you aren’t sure where to start, take a look at this YouTube video, where three different model train scales are compared by price.

Who Will Be Using Your Model Railroad?

Another thing that you’ll want to think about in choosing the right model railroad scale is who the primary operator will be. Young children and older model railroaders may have a more difficult time using trains that are on a very small scale, since they can be harder to manipulate and repair. If you’re setting up a model train set for kids to use, take a look at this guide to picking the perfect scale for a little one. It’s also worth mentioning that those with vision problems will likely find that larger equipment is much easier to see and enjoy.

What’s The Availability of Equipment And Accessories?

If you choose a scale that isn’t commonly used, you should be prepared to search for accessories in a variety of places. Some scales are used more often in different countries, which means that you could wind up having to purchase your gear overseas and have it shipped, a costly and time-consuming prospect. A good place to see what type of rolling stock, track and accessories are available for any given scale is TrainWorld, since they have a large selection of merchandise and their site allows you to shop by scale. If you’re envisioning a specific scenario for your model railway, like a Christmas village or a mining operation, try to go with the scale that is most often used in the production of its components.

A Model Train Scale Comparison

This chart offers an excellent visual of the different model train scales compared side-by-side.

model train scales explained

Image courtesy of


The Most Popular Model Train Scales

N = 1:160 Scale

The basics: N Scale model trains are the smallest of the most commonly sold scales. A typical 40’ box car will be 3.25” long x 0.75” wide x 1” high and the minimum curve radius is 9.75”.

Pros: N Scale trains allow for more realistic and complex model railway layouts, even in a limited area. N trains also operate on more gradual curves and turnouts, which will mean fewer derailments and more fun for the operator. A recent surge in popularity is likely to lead to more accessories options at this scale as well.

Cons: The smaller stock can make N scale railroads a little tougher for both young kids and older enthusiasts to operate. While it is becoming a more popular option, there can still be a bit of a struggle to find the same variety of accessories that you may see in other, more common scales, like O and HO.

It often helps to see how a model train measures up next to a person, so take a look at this YouTube video of an amazing railroad layout in N Scale and its builder to get a better idea of how it would look in your home.

HO = 1:87.1 Scale

The basics: HO was given its name because of the fact that it’s half of O Scale. This is by far the most popular of all the scales on the market on the market today. A train in HO Scale has a minimum curve radius of 15”-22” and a typical 40’ box car will be 5.75” long x 1.50” wide x 2” high.

Pros: Because of its widespread use, it’s exceptionally easy to find whatever rolling stock, track or accessories that you need or want in HO Scale. The sky really is the limit with this size model railroad and those who enjoy designing and building their own accessories will probably find it to be the one best-suited to their needs. Another benefit of the HO train scale is that the size allows for a more realistic layout than larger scales do without requiring more space.

Cons: Young model train operators may have a hard time with the HO Scale size in the beginning, but they can usually adapt to it fairly quickly. If you’re very tight on space, you’ll probably want to go ahead and go with N scale, but otherwise, there’s really no drawback to using HO.

The Medina Railroad Museum has an excellent example of a HO Scale model train set.

Picture 2

Image courtesy of a69mustang4me via Flickr


O = 1:48 Scale

The basics: O Scale is probably the size that most people associate with model train sets, since it was the size that well-known Lionel trains were manufactured in for many years. This scale has a minimum curve radius of 72” and a typical 40’ box car is 10.5” long x 2.50” wide x 3.75” high.

Pros: The size of O Scale means that it’s easier to create engines and rolling stock with enough detail that they look more realistic than smaller scales. O Scale train sets are also usually easier for kids and more mature railway modelers to operate.

Cons: The more authentic look of O Scale stock will normally come with a higher price tag attached, so be prepared to spend more on your setup than you would with an N or HO Scale model railroad. It will also need more room if you want to maintain a more realistic appearance, due to the fact that sharp turns tend to make a layout look more like a toy than the real thing.

This is a classic O Scale model train located at the Angels Gate Hi-Railers Model Railroad Club.

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Image courtesy of Atomic Links via Flickr


On30 = 1:48 Scale

The basics: A small ‘n’ in a scale description indicates a narrower gauge, so On30 means that a model railroad is O Scale but with 16.5mm track instead of the standard 32mm track that O Scale gear would typically run on. The number 30 refers to the fact that this scale and gauge combination is often used for modeling 2.5’ narrow gauge prototypes (because 2’ 6” = 30”). For the same reason, On30 might also be called On2½.

Pros: On30 Scale is optimum for mining or logging layouts, where it would be simpler and less costly to lay down a narrower track. It allows the user to run equipment that is larger and with more detail, but in a tighter space. If you’re looking to setup a Christmas village or use Dept. 56 buildings, than this is the best scale/gauge combination for you.

Cons: Because On30 Scale is such a niche market, it can be harder to find rolling stock and accessories. This means that those you do find can be a little more expensive and they may not be exactly what you’re looking for. Unless you have a good reason to use On30 Scale, you’ll probably be better-served by a more common scale size.

G = 1:22.5 to 1:29 Scale

The basics: Often referred to as Garden Scale, this is the ideal size for a model railroad setup with an outdoor layout or to run around a Christmas tree. A typical 40’ box car is 17.25” long x 4.5” wide x 6.5” high and the minimum curve radius ranges from 24” to 44”, depending on the scale, which can vary.

Pros: G Scale trains are usually especially easy for kids to use since they don’t derail as often as smaller engines. If you have an outdoor layout, it’s very easy to find rolling stock, tracks and accessories that are made to withstand the elements in G Scale.

Cons: G Scale will require a lot of space in order to operate properly and good equipment can be pretty pricey. There are also fewer accessories out there for G Scale railroads, so you may find that your options are limited. This scale has also not been standardized, so depending on your region or what online vendor you’re shopping from, you could find G Scale equipment in a range of sizes, which might make it tougher to pull together a cohesive-looking railroad.

Here’s a small G Scale model train setup that was obviously a big hit!

Picture 4

Image courtesy of TrishaLyn via Flickr

Other Commonly Used Model Train Scales

S = 1:64 Scale

The basics: S Scale trains were more popular in the 1950’s, thanks to brands like American Flyer and others. A typical 40’ box car is 7.5” long and the minimum curve radius is between 20” and 30”.

Pros: Since they’re bigger than HO scale, users can enjoy equipment that’s more detailed and stable, while still needing less room than an O Scale setup would require.

Cons: Aside from the fact that S Scale components can be hard to find, they can also be more expensive. This scale has become increasingly popular with kitbashers because of the advantages listed above, but if you’re in search of a kit or want to pull together a railway without a lot of hassle, this probably isn’t the right one for you. For those who have their heart set on S Scale, MTH Trains is a good place to look for equipment.

An S Scale setup in Bristol, England…

Z= 1:220 Scale

The basics: Z Scale is the smallest model train scale in common use, though there are two even smaller scales that aren’t used as often, known as ZZ Scale and T Scale. These micro trains are generally used to create novelty model railways in places where other scales simply wouldn’t fit, including briefcases, jewelry boxes and on coffee tables. The minimum curve radius for Z Scales trains is 4.5” to 6” and a 75’ locomotive is about 4” long.

Pros: Of course, one of the biggest benefits to using Z Scale is the sheer convenience of it, since these train sets are small enough to go virtually anywhere you want them to. An advantage that is often overlooked however, is that these micro trains allow for the turns to be relatively wide, which offers a much more realistic looking run. They can also be used to easily replicate a real scene that would likely prove difficult at a larger scale.

Cons: This is not the scale for young children, due to the fact that the tiny components are too hard for small hands to manipulate and they can pose a choking hazard. Bear in mind that your accessories may be limited by the space in which you decide to create your model when using Z Scale model trains. You also shouldn’t expect too much in the way of detail from a micro train set. The minute pieces are too small to include intricate details and the naked eye wouldn’t be able to see them even if they were there.

A briefcase railroad model in Z scale on display at the California State Railroad Museum.

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Image courtesy of Corvair Owner via Flickr

Having model train scales explained is a good place to start, but if you have more questions about choosing the right scale for your new model train set, be sure to purchase our ebook on How To Create the Model Railroad of Your Dreams! It’s the definitive guide for beginning your journey into the world of model railroading!

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Robert Thomson

Robert W. Thomson is a life-long railfan, the son of a former L&N Railroad B&B gang foreman, and an amateur photographer. He was born and raised in southeast Tennessee but now lives in Butte, Montana with his wife, Connie and cat, Charlie. Robert has worked as a park ranger, underground mine tour guide, freelance roleplaying game writer, and ran his own roleplaying game publishing company until selling it in 2012.

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About The Author

Robert Thomson

Robert W. Thomson is a life-long railfan, the son of a former L&N Railroad B&B gang foreman, and an amateur photographer. He was born and raised in southeast Tennessee but now lives in Butte, Montana with his wife, Connie and cat, Charlie. Robert has worked as a park ranger, underground mine tour guide, freelance roleplaying game writer, and ran his own roleplaying game publishing company until selling it in 2012.