About this tool
STL is the standard format for 3D printing models: a list of triangles without unit, colour or material. The STL viewer shows the file as a rotatable 3D preview and measures dimensions, volume and surface area. The file is not uploaded but read right in your browser, binary as well as ASCII.
The mesh check counts open edges (holes), edges shared by more than two triangles and triangles with flipped orientation. Only for a watertight mesh is the volume correct. From volume and surface the tool also estimates weight and filament length: a solid shell under the whole surface plus infill inside.
How it works
- Choose an STL file or drop it into the box; there is an example to try it out.
- Check the unit: STL files have none, usually it is millimetres.
- Rotate the model in the preview and read dimensions, volume and the result of the mesh check.
- Set infill, shell and material to estimate weight and filament length.
Frequently asked questions
Is my file uploaded?
No. The STL file is read and analysed in your browser and never leaves your device. That also works for confidential designs.
What does “not watertight” mean?
The mesh has holes, edges with more than two faces or triangles facing the wrong way. Slicers can often still print or repair such models, but volume and weight are then not exact. You can repair them e.g. in PrusaSlicer, OrcaSlicer or Meshmixer.
How accurate is the filament estimate?
It is a rough guide. The tool assumes a solid shell of the given thickness under the whole surface and fills the rest with the chosen infill. Supports, brim, purge and the slicer’s actual paths are missing. What the print costs is calculated by the 3D Print Cost Calculator.
Why is my model far too small or too large?
STL only stores numbers without a unit. Models from some programs are made in inches or centimetres. Switch the file unit; dimensions, volume and estimate are converted. The Filament Calculator converts a weight to a length.