What does this calculator do?
Scale dimensions and show cubic solid-volume growth. STL has no declared unit, so verify a known dimension.
How to use the calculator
- Collect measurements and check units.
- Re-slice mass and time. Check walls and joints; nonuniform scaling can make round holes elliptical.
- Record assumptions and check the result before applying it.
How the calculation works
Dimensions multiply by scale; volume multiplies by scale³
Factor = desired/reference. Dimensions multiply by factor; solid volume by factor³, or sx × sy × sz for independent axes.
Practical calculation example
40 × 20 × 10 mm uniformly scaled by 1.5 becomes 60 × 30 × 15 mm and solid volume grows by 3.375.
Understanding the results
Re-slice mass and time. Check walls and joints; nonuniform scaling can make round holes elliptical.
Uniform scaling changes every axis
Enter original X, Y and Z dimensions and a percentage scale. At 100% they remain unchanged; 150% multiplies every axis by 1.5. The calculator previews the new bounding dimensions without modifying a file. Use one orientation and unit system. If inches were imported as millimetres, establish that mismatch first. A guessed visual correction can hide the underlying error and make later measurements difficult to reproduce. Keep the original model so the transformation remains reversible.
Lengths and volumes have different factors
Let s equal percentage divided by 100. Each length multiplies by s. Geometric area multiplies by s² and enclosed geometric volume by s³. The tool reports the volume multiplier, not actual filament consumption. Hollow or infilled parts can have a different consumption ratio because wall counts, line widths and support strategy may stay fixed. Distinguish geometric transformation from the manufacturing decisions made when the resized model is sliced.
A complete numerical example
A 40 × 30 × 20 mm model at 150% becomes 60 × 45 × 30 mm. Its linear factor is 1.5 and geometric volume factor 1.5³ = 3.375. An identical fully solid shape has 3.375 times its original volume. Do not apply that multiplier automatically to print time or production cost. Slice the new model for fresh material and duration estimates, then use those estimates in cost and finish-time calculations.
Functional interfaces also change
Uniform resizing changes holes, snap features, clearances and mesh-defined walls. A model designed for an existing screw may no longer fit it. If only one interface needs adjustment, edit CAD or use an appropriate local compensation instead of resizing everything. Shrinkage compensation should come from cooled measurements and a proportional error, not a first-layer bulge or fixed hole offset. An attractive outer dimension is not enough to confirm a functional fit.
Inspect the resized geometry
Check new dimensions against build volume, including brim and supports. Shrinking can make thin features vanish or become variable-width paths. Enlarging a coarse STL cannot restore missing geometric detail and may make faceting visible. Prefer a suitable-resolution export from CAD over repeatedly transforming a coarse file. Inspect the slicer preview for small holes, walls, text and overhangs. Preserve the exact scale factor with the project so a future replacement part uses the same geometry.
Reslice before estimating resources
After scaling, choose orientation and slice with the intended profile. Compare part mass, supports, purge and duration with the original job. A larger part may require different cooling, support placement or strength tests despite proportional shape. This calculator supports uniform scaling only. Non-uniform axis factors belong in CAD or a slicer and can distort circles and interfaces. Their volume multiplier is the product of all three axis factors, not the cube of just one of them.
Advanced tips
- Re-slice mass and time. Check walls and joints; nonuniform scaling can make round holes elliptical.
Common mistakes
- Using the cubic geometric volume multiplier as an automatic print-time prediction.
Frequently asked questions
Does doubling size double the material?
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Doubling all three dimensions gives eight times geometric volume. Real printed consumption depends on the new slice.
Can I scale just one axis here?
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No. The tool applies one uniform factor. Use CAD or a slicer for non-uniform scaling and inspect the resulting distortion.
Sources & methodology
Mathematical results depend on the supplied inputs. Material properties and machine limits need confirmation for your exact equipment. Editorial specialist approval remains pending.