Ring Sizes

I finally lost my wedding band. As a machinist type person, it comes off all of the time for safety. At the end a day last week it wasn’t in my pocket where I put it. Sucks.
It’s a pretty good design. Stainless is the ultimate ring material. Super slim and strong with a really pretty shine.
The good news is that I had a print of it so I can make another to the same spec. This is the best ring size chart I could find. The numbers aren’t to a formula. All of the charts I found are all over the map. Don’t trust ring sizes

I take a 10.95 ring at a 4.5mm width. Width is a factor to sizing so it should be noted.

US ring sizes are a mess. It’s not so much a standardized system, I went to the ISO 8653:2016 standard which is (simply) the inner circumference in millimeters. I converted back with ISO = 2.55 * NA + 36.5. It may not be perfect but it’s a lot better than any other system I looked into.