Self Defense and the Art of Jewelry Buying - Size Your Finger, Not Your Ring
Because it can never be stated enough, here’s some advice on getting accurate ring sizes. First, DON’T use a paper ring sizer that you print off yourself. Second, the string method doesn’t work either. Third, please please PLEASE go to a jewelry store or jewelry counter and have them size you with a wide band (wedding band) metal ring size finder. That’s really the best method.
In a pinch, if you know the size of another ring that you normally wear on the finger you’ll be wearing your new ring on, you can use that. However, if it’s been a bit, you should probably get your size checked, especially if you’ve noticed that the older ring might not be fitting the same as it did when you first started wearing it.
If upon receiving your new ring, you decide that it doesn’t fit quite right, go get your finger sized, not your ring! Although it is true that not all ring mandrels are created equal, in fact there can be some ridiculously wild differences among certain brands, reputable jewelers will use mandrels that closely correlate to the metal ring size finders and so in all likelihood the ring will have been created to the size you specified.
Basically, when in doubt, go to a professional! If you find that you can’t, for whatever reason (because let’s face it, you don’t always have time to pop off to a brick-and-mortar jewelry store), there are adjustable plastic belt-style ring size finders that are fairly accurate and pretty inexpensive that you can order from various places online.