Question about units

Support Basics & Interface
1

I have my units set for metric / unit scale 0.01 for millimeters. I measure models inside Blender and it says mm but when I export it to a 3D printing site it is in DECIMITERS! What is going on here?

Thanks

2

Well in fact for STL files (from Wikipedia) :

STL files contain no scale information, and the units are arbitrary

You may have a look (for example) here:

3

Got it. I had my units set up wrong…