Model Scale Calculator

Uniform scaling multiplies every axis by the same factor. A 100 mm dimension at 150% scale becomes 150 mm. Volume scales with the cube of the factor — 150% scale uses 3.375× the material (1.5³), not 1.5×.

Slicers apply scale in the prepare stage before slicing. After scaling, verify fit on the build plate and check minimum feature sizes — tiny details may become unprintable when scaled down.

Example: 80 mm tall figure scaled to 125% → 100 mm tall. Material volume increases by 1.25³ = 1.95× — nearly double the filament.

The square-cube law is why scaling surprises people. Dimensions grow linearly, surface area with the square, and volume with the cube, so a model at 200% is twice as tall but uses eight times the material. Print time lands somewhere between the square and the cube, because taller parts need more layers and each layer covers more area.

Scaling up weakens parts in relative terms even as it strengthens them absolutely. Mass grows with the cube while the cross-section carrying the load grows only with the square, so a doubled model carries eight times the weight on four times the area — thin spans, outstretched arms, and slender stems are the first things to sag or snap.

Wall thickness does not survive scaling down. A 1.2 mm wall at 50% becomes 0.6 mm, which may be a single line or fall below what your nozzle can produce at all, so features silently vanish rather than printing thin. Check the scaled model in layer preview, not just the outline.

Holes and clearances scale too, which breaks mechanical fits. A 3 mm hole sized for an M3 screw becomes 2.4 mm at 80% and no longer accepts the fastener, and articulated joints designed with a specific gap will either bind or go slack. Model in critical dimensions where possible, or ream and drill after printing.

Non-uniform scaling is a different operation with different consequences. Stretching one axis distorts circles into ellipses and changes overhang angles, which can push surfaces past what your printer can bridge unsupported — apply per-axis scaling in the slicer and re-slice, since scale is applied before slicing.

Resizing changes volume cubically — after scaling dimensions, rerun print volume and filament weight tools with the new bounding box before quoting material cost to a client.

Scaling down fine text or thin pins below your printer minimum feature size may disappear — inspect the scaled mesh in the slicer layer view before starting a long print.

Articulated joints may bind when scaled down — test fit tolerance on one joint before printing an entire scaled assembly.

Hole diameters shrink when scaled down — drill or ream critical bores after printing if mechanical fit must be exact.