STL 3D Print Cost Calculator

The tool parses the STL mesh and computes volume with the signed-tetrahedron sum (V = |Σ a · (b × c) / 6|), the same method slicers use, so the volume is exact for a watertight mesh — not an approximation from the bounding box.

Material usage accounts for both the shell and the infill:

material = min(V, infill × V + surfaceArea × shellThickness × (1 − infill))

This matters more than most calculators admit. A solid cube at 15% infill uses roughly a quarter of its volume, but a hollow, high-surface-area model like 3DBenchy uses over 60% — because the shell dominates. Using a flat “infill multiplier” can be off by 2× or more, so this tool uses the mesh's real surface area instead.

Densities come from manufacturer technical data sheets (Prusament, Bambu Lab, Polymaker, eSUN). Note that matte PLA is about 6% denser than standard PLA (1.31 vs 1.24 g/cm³), and ASA ranges from 1.05 to 1.13 depending on brand — you can override the density and price for your exact spool.

Print time is estimated from volume divided by an effective flow rate. Note this is not the printer's maximum volumetric speed (MVS): travel moves, acceleration and layer changes mean real average flow is typically 15–50% of MVS. The presets here are back-calculated from real benchmark prints (e.g. a Benchy in 37 minutes on a Prusa MK4S ≈ 4.3 mm³/s). Expect ±40% accuracy; only your slicer's G-code estimate is authoritative.

Once you run a few estimates, the pattern is clear: time costs more than filament — machine occupancy if you print for clients, patience if you don't. These levers matter, roughly in this order:

• Lower the infill — 15% → 10% is fine for many parts. But note from the formula above: on high-surface-area models the shell dominates, so the saving is smaller than you'd expect
• Change the orientation — less support means less material and less time. This is the biggest variable the calculator can't see for you
• Hollow the model in CAD — more effective than any infill setting
• Use a bigger nozzle — 0.4 → 0.6mm roughly halves print time when fine detail isn't needed

• PLA — prototypes, models, indoor parts. Cheapest and easiest, but deforms above ~50°C (a hot car will ruin it)
• PETG — outdoor and functional parts, more impact-resistant than PLA
• ABS / ASA — heat and weather resistance; needs an enclosure. ASA is the UV-stable choice for outdoors
• TPU — flexible parts (gaskets, phone cases); prints slowly
• Nylon / PC — mechanical, high-strength parts. Hygroscopic, so drying is mandatory
• CF blends — stiff and low-warp, but roughly double the price and require a hardened nozzle

Privacy

The STL is read with the File API and parsed in your browser's memory. Nothing is sent to our servers — useful when your model is confidential or a client's IP.

FAQ

Does it support both binary and ASCII STL?

Yes. Binary files are detected by checking the file size against the header's triangle count (84 + 50n) rather than the leading “solid” keyword — many binary STLs, including the official 3DBenchy, start with “solid” and would otherwise be misread.

Why is my volume suspiciously large?

The mesh is probably not watertight (holes or flipped normals). The tool warns when computed volume exceeds the bounding box. Repair the mesh in your slicer or in Meshmixer/Blender for an accurate figure.