I'm searching for "the" US Ring standard measurement and seem to find different measurements from different sizing charts. What formula do you use for the ring conversion? Can you direct me to a reference for the formula or the standard measurement?
Re: US Ring sizes
by Robert Fogt on 11/30/04 at 13:05:58
There is no reference to a standard measurement, as U.S. ring sizes have never been standardized.
The formula used is: A ring of size n has a circumference of 1.43 + (0.102 * n) inches.
It doesn't say how that formula distinguishes between sizes 0, 00, 000, etc. I guess those sizes are exceptions to the rules.
What I did to create the chart used here, was first consolidate data from around the internet, then I emailed the list of data to every online jewler I could find. Then I fine tuned the data from the input of those jewlers who responded.