How to measure a 3MF file
- Choose or drop a
.3mffile. - Inspect the width, height and depth of the resolved build geometry.
- Confirm the declared 3MF unit and compare converted measurements with your intended size.
- Enter your printer's usable build volume to check whether the model fits before slicing.
Why 3MF dimensions are more reliable than STL dimensions
3MF can store a model unit, so a 3MF file carries more scale information than a basic STL file. This checker uses that declared or effective 3MF unit when displaying the final build dimensions. STL does not reliably carry unit metadata; use the STL Dimensions Checker when working with STL files.
Build items can change the final size
A 3MF package can contain several objects and place them into a build with transforms. This checker measures the resolved build geometry after those placements, rather than measuring only the first object stored in the package. Separate parts are not automatically a problem, but their combined bounds may be larger than any individual object.
Printer fit is a useful first check
The printer-fit result compares the model's axis-aligned dimensions with the build volume you enter. It does not account for printer margins, orientation, supports, brim/raft, nozzle clearance or slicer settings. Always confirm the final placement in your slicer.
For a focused closed-surface check, use the 3MF Watertight Checker.
For open-edge and non-manifold-edge counts, use the 3MF Manifold Checker.
FAQ
Does my 3MF file get uploaded?
Yes. The checker uses the same secure processing flow as other InspectMesh analysis tools to calculate the result. It is not a browser-only viewer. For local viewing without upload, use the 3MF Viewer.
Are the dimensions measured before or after build-item transforms?
They are measured from the resolved build geometry, including supported build-item and component transforms.
Does a fitting result guarantee that I can print the file?
No. It is a size comparison only. Your slicer, chosen orientation, supports, printer margins and print settings still matter.
Can I use this tool for STL files?
Use the STL Dimensions Checker. STL coordinates do not reliably specify their intended unit.