Open an STL or OBJ file to get its bounding box, volume, surface area, and an estimate of the PLA filament needed to print it solid.
The file is opened locally in your browser and is never uploaded.
This checker parses STL (binary or ASCII) or OBJ files and measures the mesh. The bounding box is the size of the smallest axis-aligned box containing the model. Volume is computed with the signed tetrahedron method, summing the signed volume of tetrahedra formed by each triangle and the origin, then taking the absolute value, which gives the enclosed volume of a closed mesh. Surface area is the sum of all triangle areas. Filament estimates treat that volume as solid PLA at 1.24 g per cubic centimetre, and divide the volume by the cross-section of 1.75 mm filament to give a length. Models are assumed to be in millimetres; neither STL nor OBJ stores a reliable unit, and millimetres are the slicer convention.
Why is the filament estimate higher than my slicer shows? This checker assumes a completely solid model. Slicers use shells and partial infill, so real filament use is normally lower. Treat the figure as an upper bound.
What units does the checker use? Millimetres throughout. If a model was designed in inches or centimetres, its numbers will be off by that scale factor, because STL and OBJ do not record units reliably.
Does volume work on open meshes? The signed-volume method assumes a closed mesh. Holes or flipped triangles make the volume inaccurate, so check suspect files with a mesh checker first.