Free plastics and 3D printing calculators

Credits and licences

Last updated 2026-10-11

Our own code

The tools and page layouts are written for this site. The pages make no requests to other servers.

Data and formulas

The calculators use published definitions, typical values and textbook formulas, typed into our own code (no third-party tables or libraries are copied):

  • Plastic and filament densities: typical values, labelled as such on each page (grades vary; use the supplier’s datasheet).
  • Resin identification codes: the ASTM D7611 coding system; the symbols are drawn by us.
  • Units: 1 mil = 0.001 in = 25.4 µm (exact), US gallon = 231 in³, film gauge = mil × 100.
  • 3D printing, epoxy, heat shrink, can liner and clamp force calculations: geometry and standard formulas written out in each calculator’s steps.

Third-party material

None at present. If we add any library, font or data set, it will be listed here with its licence and a link (data/credits.json, rendered below).