Model scale calculator
Convert a real-world dimension to model size—or work backwards from a model measurement—at any 1:N scale. The calculation runs in your browser and the formula is shown below the result.
Method and page checked: August 13, 2026.
Convert a dimension
Model length at 1:72
138.889 mm
10 m ÷ 72 = 138.889 mm
The formulas
Real size to model size: model length = real length ÷ scale denominator.
Model size to real size: real length = model length × scale denominator.
Units are first converted through millimetres, then the scale formula is applied, and finally the answer is converted to your selected output unit. For example, a 10 m object at 1:72 is 10,000 mm ÷ 72 = 138.889 mm.
Common modelling scales
| Scale | Common uses |
|---|---|
| 1:12 | Dollhouses, large figures |
| 1:24 | Large cars, miniatures |
| 1:32 | Aircraft, slot cars |
| 1:35 | Military vehicles |
| 1:48 | Aircraft, O scale-adjacent models |
| 1:64 | Die-cast cars |
| 1:72 | Aircraft and military kits |
| 1:87 | HO model railways |
| 1:144 | Aircraft and spacecraft |
| 1:350 | Ships |
What this calculator does not estimate
Scale is geometry, not difficulty. This tool does not estimate part count, build time, tab fit or skill level. Many fantasy, decorative and mechanical metal kits do not reproduce a real object at a standardized scale; if the maker does not state a scale, do not infer one from this calculator.
Accuracy and reuse
Results use exact unit factors and are rounded for display. You may link to this calculator as a free reference. If you spot an error, please send us the inputs and expected result so we can check it.