Boneyard Tools

Infill Weight Calculator for 3D Prints

Enter a model volume and an infill percentage to get a rough filament weight and length. This is a planning estimate that ignores walls and solid top and bottom layers.

How to estimate infill weight

  1. Find your model volume in cubic centimeters from the slicer or CAD tool.
  2. Enter the infill percentage you plan to print.
  3. Pick the material so the density matches, or keep PLA.
  4. Read the rough filament weight and length.

Examples

100 cm3 at 20% PLA

volume 100 cm3, infill 20%, PLA 1.24
about 24.8 g (around 8.3 m)

A solid 50 cm3 part

volume 50 cm3, infill 100%, PLA 1.24
about 62 g

Frequently asked questions

How accurate is this estimate?

It is a rough planning figure. Weight equals volume times infill fraction times density and ignores perimeter walls, top and bottom solid layers, supports and brims, so real prints weigh more.

Why does the slicer report a higher weight?

Slicers add solid walls, floors, ceilings and supports on top of the infill, which this simple model leaves out. Small or thin parts differ the most.

What density should I use?

Common densities in g/cm3 are PLA 1.24, ABS 1.04, PETG 1.27, TPU 1.21 and Nylon 1.14. The default here is PLA at 1.24.

How is the filament length found?

The grams are converted back to a solid plastic volume, then divided by the 1.75 mm round cross-section area to get meters of filament.

When is this estimate closest to reality?

For large, chunky models with thin walls relative to their bulk, where infill dominates the total plastic used.

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