Scaling a model to an exact size
Slicers scale by percentage. To make a part exactly 120 mm wide when it is 80 mm now, scale by 120 ÷ 80 = 150% on all axes.
Scale % = target size ÷ current size × 100
Tiny model? It was probably exported in inches
If a model shows up 25.4 times too small, it was designed in inches. Scale it by 2540% to convert inches to millimeters. If it is 10 times too small it was likely in centimeters (1000%).
Scaling changes everything: screw holes, clearances and wall thickness. For functional parts, resize in CAD instead.
Frequently asked questions
What does 2540% scale mean?
It converts a model made in inches to millimeters (1 inch = 25.4 mm).
How do I scale an STL to a specific size?
Divide the size you want by the current size and use that percentage uniformly in the slicer.