Which scale should I choose?

It depends on available space, budget, detail level and what others in your club build. 1:72 is popular for aircraft because it balances detail with shelf space. 1:35 is the standard for armour. For railways, OO (1:76) is the UK standard and HO (1:87) is the international standard. This calculator helps you visualise how big your subject will be at each scale.

Why are there so many different scales?

Scales evolved from different traditions. Aircraft scales (1:72, 1:48, 1:32) are based on dividing a foot into convenient fractions. Railway scales relate to track gauges. Wargaming scales (28mm) refer to figure eye height. Die-cast collectors use 1:43 and 1:18 because of toy industry standards.

How much bigger is 1:48 than 1:72?

A 1:48 model is 50% larger in each dimension than 1:72 (72/48 = 1.5). In area it is 2.25 times larger, and in volume 3.375 times larger. This comparison calculator makes these differences immediately visible.

ModelCalcs

Scale Comparison Calculator — Side by Side

Enter a real-world measurement and see the model size at every common scale, side by side. Great for choosing a scale for your next project.

Real-World Measurement

Enter the real dimension in millimetres (e.g. 10m = 10000mm)

Display UnitChoose how model sizes are shown in results

Subject TypeHighlights the most common scales for your subject type

How We Calculate This

This calculator divides your real-world measurement by each standard scale factor to produce a comparison table.

Formula

Model size = Real size ÷ Scale factor (applied for each scale)

Example: A 10m (10,000mm) real length produces: 1:48 = 208mm, 1:72 = 139mm, 1:144 = 69mm, 1:350 = 28.6mm.

Note: 1:76 (OO), 1:87 (HO) and 1:148 (UK N) are the standard hobby abbreviations of the precise prototype ratios 1:76.2 (4mm to the foot), 1:87.1 (3.5mm to the foot) and 1:148. The rounding is well under 0.3% — for a 10m subject the OO result differs by about a third of a millimetre — so the integer ratios shown here match what manufacturers print on the box.

Frequently Asked Questions

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Mixed Scale Calculator

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Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.