How to Resize an STL Model for 1:64 Scale
One number, entered in the slicer, and you are done
You do not need to edit the mesh. The slicer does the scaling.
IN SHORT
- Scale in the slicer, not in the mesh. It is reversible.
- The percentage is (source N ÷ target N) × 100.
- Scale all three axes equally, or the model prints squashed.
- A model designed at 1:64 prints better than one scaled down.
1.5625%
Real size (1:1) scaled to 1:64
37.5%
A 1:24 model scaled to 1:64
67.1875%
A 1:43 model scaled to 1:64
0.4 mm
Typical minimum wall thickness to print
WHERE TO SCALE
Scale in the slicer, not in the mesh
Almost every slicer has a scale field that applies to the whole model.
It is reversible. You change one number and print again, with no risk to the original file.
You also keep the source file at its native scale, so you can print it at 1:64 and at 1:43 from one download.
THE FORMULA
The formula
It is the ratio of the two denominators, expressed as a percentage.
The known scale N is what the model represents now: 1 if it was modelled at real size, 32 if it was downloaded as a 1:32 model.
The same ratio as a length conversion is: target dimension = known dimension × (known N ÷ target N). Divide one by the other to identify a source scale.
WORKED NUMBERS
Worked examples
The numbers you will type, all with a target of 1:64.
Most slicers accept decimals, so type the exact figure. The difference between 1.5625% and 1.6% is about half a millimetre on a 70 mm car.
The ToolHuts Model Scale Converter computes the percentage for any pair of scales and exports a printable scale bar, with no account.
Scaling down to 1:64: the percentage to enter in the slicer
| Model is currently | Calculation | Enter in slicer |
|---|---|---|
| Real size (1:1) | 1 ÷ 64 × 100 | 1.5625% |
| 1:12 | 12 ÷ 64 × 100 | 18.75% |
| 1:18 | 18 ÷ 64 × 100 | 28.125% |
| 1:24 | 24 ÷ 64 × 100 | 37.5% |
| 1:32 | 32 ÷ 64 × 100 | 50% |
| 1:43 | 43 ÷ 64 × 100 | 67.1875% |
| 1:64 | 64 ÷ 64 × 100 | 100% (no change) |
| 1:72 | 72 ÷ 64 × 100 | 112.5% |
| 1:87 | 87 ÷ 64 × 100 | 135.9375% |
ONE AXIS AT A TIME
Uniform versus per-axis scaling
Scale all three axes by the same factor, or the car comes out flattened.
If you need a non-uniform change, do it in the mesh editor and check the result from three angles before printing.
UNKNOWN SOURCE SCALE
If you do not know the source scale
Plenty of STL files have no scale information. Measure something you recognise.
The resources and database category includes a free converter that handles the arithmetic once you have the source scale.
-
Measure a known dimension
Divide a real size by the model size. A 32 mm door against 2,030 mm gives 1:64.
-
Use a reference object
The scale reference guide lists the roller door, car, interior door and sign sizes.
-
Print a test at 100% first
Print it, hold it next to your car, and measure. Adjust the percentage and reprint.
BEFORE YOU PRINT
Checks before you print
Two things go wrong after a scale change, and both are easy to prevent.
Layer height matters too. At 0.2 mm layers a 0.4 mm wall is two layers, and a 0.2 mm wall is one, which is fragile.
SOURCES
Where to find STL files
The 3D printing category collects free repositories and 1:64 specific designers.
Check what scale the designer modelled at before downloading, and whether a pre-scaled variant exists. Files designed for 1:64 already account for minimum wall thickness.
What percentage do I scale an STL to 1/64?
It depends on the current scale. A real-size model needs 1.5625%, a 1:32 model 50%, a 1:24 model 37.5% and a 1:43 model 67.1875%.
Can I change the scale of an STL file?
Yes, and you do not need to edit the mesh. Every slicer has a scale field that applies to the whole model.
Why does my scaled model look squashed or distorted?
Almost always because the scale was applied to some axes and not others. Check that X, Y and Z carry the same percentage.
What is the smallest detail a 1/64 print can keep?
Your printer's minimum wall thickness, typically 0.4 mm at a 0.4 mm nozzle. Models designed at 1:64 print better than scaled-down ones.
Keep Building
The directory collects 36 vetted resources for 1/64 scale dioramas, from scratch-build blogs and STL repositories to forums, stores, and model databases.
1:64 Scale Reference: Real Sizes & Conversions
Exact model dimensions for cars, figures, doors, signs and props, plus conversion tables for every common scale.
How to Build a 1:64 Scale Diorama
The full beginner method: planning, base, textures, scale check, paint, light, and photography.
1/64 Garage Diorama: Ideas, Kits & Build
Garage dimensions, four DIY construction methods, and where to buy ready-made kits.
NEXT STEP
Find the part you are missing
Every guide links to the category that covers where the parts come from. Browse the full directory when you would rather see everything in one place.