Welcome to the forum!
I like the mm measurements better than the gauge system, which makes it way too easy to skip sizes without even knowing it. I learned about stretching on a forum based in the UK so I memorized the gauge/mm conversions pretty quickly (except in huge sizes).
I have 1/2" lobes and 11 piercings: left helix x2, both conches, both nostrils, septum, navel, and VCH.
My lobes are small but I know a lot about stretching and how to do it safely, so message me if you have any questions!