We know that 3D printed parts often do not match the CAD dimensions of their print files. For many surfaces this is of no consequence. Interface dimensions that are off by more than a little may require work to fix, or can result in scrap parts. To improve the odds of success, I have created a few simple test prints:
The attached STL files are intended to be printed so that you can measure the resultant test prints, to see how closely your printer, material and slicer settings result in matching CAD specs. You would choose a fast printing test print or prints, near the dimensions of the more complex parts you care about, and use the results to tune printer parameters before starting long complex parts. This is more important when parts have to fit with or inside other parts.
There are a range of test print sizes because the extent to which walls are off varies by absolute dimension - especially for the ID of cylindrical holes. This, while flat walls may print with a more or less fixed error, for given printer settings.