Common Scale Modelling Maths - Worked Answers
The ten questions modellers ask most, with ready-to-paste answers for Reddit or Facebook comments. Each one links straight to the calculator that does the maths for you.
How tall is a 6 ft figure in OO scale (1:76)?
Quick maths for a 6 ft (183 cm) figure in OO, 1:76: 1830 mm ÷ 76 = 24.06 mm ≈ 24 mm to the top of the head. If the manufacturer measures to eye level instead, expect around 22-23 mm, so always check which convention they use.
What percentage do I resize a 1:35 STL to print it at 1:48?
Going from 1:35 down to 1:48: 35 ÷ 48 = 0.729 → resize the STL to 72.92%. Example: a 200 mm long hull printed at 1:35 becomes 200 × 0.729 = 145.83 mm at 1:48.
Can I mix 28 mm and 32 mm figures in the same diorama?
Mixing 28 mm and 32 mm figures: 32 ÷ 28 = 1.14, so a 32 mm figure is about 14% taller. That is noticeable side by side. Most modellers either stick to one size, or place the larger figures slightly further back in the scene to disguise the difference.
What scale is N gauge?
N gauge vs N scale: - UK N gauge is 1:148 (4 mm scale feet + 9 mm track gauge). - N scale in the US, Europe and Japan is 1:160. A 6 ft (1830 mm) person works out at 12.4 mm in 1:148 or 11.4 mm in 1:160, so UK figures run slightly larger than imports.
How big is a 1:35 tank if the real one is 6 m long?
1:35 conversion for a 6 m (6000 mm) tank: 6000 mm ÷ 35 = 171.43 mm ≈ 17.1 cm on your shelf. That is why even a "small" 1:35 armoured car needs serious shelf space once built.
How tall is a 1:12 scale person?
1:12 (fashion dolls and figure scales): An 1800 mm (6 ft) person ÷ 12 = 150 mm, so a 1:12 adult figure stands about 15 cm tall. A 1650 mm person comes out at 137.5 mm.
How big is a 4 m building in HO scale (1:87)?
HO, 1:87 conversion for a 4 m (4000 mm) building: 4000 mm ÷ 87 = 45.98 mm, so roughly 46 mm long on the layout. A 20 m (20000 mm) terrace house would be 229.89 mm, about 23 cm.
Can I mix 1:43 and 1:48 diecast models on a shelf?
Mixing O gauge (1:43) and 1:48 models: 48 ÷ 43 = 1.12, so a 1:43 model is about 12% bigger than the same vehicle in 1:48. On a display shelf that reads as a size mismatch; most collectors keep the two on separate shelves or judge each model individually.
My figure measures 25 mm tall - what scale is it?
Working out scale from a measurement: A 6 ft (1828.8 mm) person ÷ 25 mm model = 73.15, so the closest common scale is 1:72 (just 1.6% off). If it measures 24 mm, the ratio is 76.2 and it is almost exactly OO, 1:76.
What is 1 metre of real life in the common modelling scales?
One metre (1000 mm) of real life in the popular scales: 1:148 → 6.76 mm 1:120 → 8.33 mm 1:87 → 11.49 mm 1:76 → 13.16 mm 1:72 → 13.89 mm 1:64 → 15.63 mm 1:56 → 17.86 mm 1:48 → 20.83 mm 1:35 → 28.57 mm 1:24 → 41.67 mm 1:12 → 83.33 mm