Model Railroad Tool

Model Train Scale Calculator

Convert real-world measurements to any model scale. Build perfectly proportioned layouts every time.

Z (1:220)N (1:160)TT (1:120)HO (1:87)S (1:64)O (1:48)G (1:22.5)

Select Model Scale

The most popular scale, offering a good balance of detail and space-saving.

Real-World Object Size (feet)

Scaled Model Size

6.90 inches

For a real-world object of 50 feet in HO scale.

Complete Scale Reference Guide

Compare all popular model train scales at a glance

Scale	Ratio	mm per Foot	Best For
Z	1:220	1.38 mm	The smallest commercially available scale. Perfect for expansive layouts in tiny spaces.
N	1:160	1.91 mm	Smaller than HO, ideal for layouts where space is limited or for long mainline runs.
TT	1:120	2.54 mm	Popular in Europe, sits between N and HO scales. Good space/detail balance.
HO	1:87	3.5 mm	The most popular scale worldwide, offering a great balance of detail and space-saving.
S	1:64	4.76 mm	Larger than HO but smaller than O. Known for American Flyer trains.
O	1:48	6.35 mm	Larger and more detailed than HO. Popular for indoor and outdoor layouts.
G	1:22.5	13.55 mm	The largest common scale, perfect for garden railways and outdoor displays.

Real-World Equivalents

See how a 50-foot real boxcar translates across different scales

2.7"

6.9 cm

50ft boxcar in Z scale

3.75"

9.5 cm

50ft boxcar in N scale

6.9"

17.5 cm

50ft boxcar in HO scale

12.5"

31.8 cm

50ft boxcar in O scale

What Can You Scale?

Convert anything from the real world to your model layout

Rolling Stock

Locomotives, boxcars, passenger cars, cabooses

Buildings

Stations, depots, factories, houses, stores

Scenery

Trees, vehicles, people, animals, signs

Terrain

Mountains, bridges, tunnels, rivers

Pro Tips for Scale Modeling

Stick to One Scale

Mixing scales can make your layout look unrealistic. Choose one scale and commit to it for all elements.

Measure Twice, Cut Once

Always double-check your calculations before cutting materials. Small errors become very noticeable at model scale.

Consider Your Space

N and Z scales are perfect for apartments. HO offers the best detail-to-space ratio. O and G are ideal for dedicated rooms or gardens.

Use Reference Photos

When modeling real structures, find photos with people or known objects for accurate size reference.

Frequently Asked Questions

What is the most popular model train scale?

HO scale (1:87) is the most popular worldwide. It offers the best balance of detail, availability of products, and space requirements. It's estimated that HO accounts for about 50% of the model train market.

What scale is best for beginners?

HO scale is typically recommended for beginners due to the wide availability of locomotives, rolling stock, buildings, and accessories. The size is easy to handle, and there's a huge community for support.

Can I mix different scales on the same layout?

While technically possible, it's not recommended. Mixing scales will make your layout look unrealistic and disproportionate. The only exception might be forced perspective in the background to create depth.

What's the difference between scale and gauge?

Scale refers to the size ratio of the model (like 1:87 for HO). Gauge refers to the distance between the rails. While related, they're not the same—different scales can sometimes share the same gauge.

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