Tool to measure in STL files



I want to create parts for a 3D printer using OpenSCAD. Having some STL files from the vendor, but nothing else (no technical drawing, no CAD files).

Does anybody knows a free tool, that allows me to

  • measure distances between 2 selected vertices,
  • measure distances between a selected vertex and a plane defined by 3 vertices,
  • measure the radio of a circle defined by 3 selected vertices?

I very much like the way Blender allows to work with meshes, especially select vertices or planes, but unfortunately haven't found a way to measure with Blender.

Thomas S.

Posted 2017-01-01T14:49:33.857

Reputation: 833


As far as I know, there is no real size information saved in .stl files, only relative positions of points in a generic unit measure. When opening an STL-file, you will have to specify how long one "unit" is. Most editors probably use millimeters or inches by default, but mixing them up will yeild results such as this. Just thought you should know. :)

– Tormod Haugene – 2017-01-02T11:21:07.107

At thingiverse, for example, you often find only STL files that print in the right size, so the values in the files seem to be mm. – Thomas S. – 2017-01-02T14:36:17.233


There is also a Blender community here on the Stack Exchange network if you have more general questions about Blender.

– tbm0115 – 2017-01-03T06:08:33.260



I suggest blender. It's not the simplest of tools but it is free and learning it will improve your 3d printing skills. :-) (I write this answer also for future viewers of this question so I start basic).

Check here for another answer:

  1. Import your STL-file.
  2. Press the Home key to view everything.
  3. Select the model by clicking on it with your left mouse button. (Blender changed to left-click-select as of version 2.80)
  4. Hit tab to enter edit-mode.
  5. Press N (or use View | Properties) until the Properties panel shows up.
  6. Select the "Length" checkbox in the "Edge Info" section of the Properties panel (see image below).
  7. Select "Edge Select" mode (see image below)
  8. Select the edge to measure by clicking on it with your right mouse button.

Edge length

enter image description here

If you need to measure the distance between to vertices with no edge. Create the edge by selecting them and pressing F. If you need to measure the distance between a vertex and any other point, select it and press E to extrude.


Posted 2017-01-01T14:49:33.857

Reputation: 632

Blender also has a tool to measure: Ruler and Protractor independent of edges.

– Thomas S. – 2017-01-02T11:09:55.553


If you're running Windows, MS 3D Builder has a measuring tool and may already be installed on your machine.

Joel Coehoorn

Posted 2017-01-01T14:49:33.857

Reputation: 1 742


Meshmixer has various measuring tools for STLs as well


Posted 2017-01-01T14:49:33.857

Reputation: 2 532