This ring sizer is off by like a 1/4 size. So lame. If I had bought an expensive ring based on this, I would have been so upset!! Do not buy this!!! Instead get the purple plastic one on Amazon as that one is accurate. I tested it with my vintage ring mandrel that my Grandma gave me from working at a diamond company back in the day.

I took these too 2 independent jewelers to confirm the accuracy of the rings, both agree these are spot-on. But read the ring sizes carefully. Some are missing. My girlfriend wears a 4.75, but this set only has a 4.25 and a 5....why did they skip two sizes and not include the more obvious 4.5 size? Same with 6, 6.25 and 7...meanwhile they offer 5.25, 5.5, and 5.75....inconsistency is why I took off 1 star.

USA sizes: 1, 2, 2-¼, 3, 3-¼, 3-½, 4, 4-¼, 5, 5-¼, 5-½, 6, 6-¼, 7, 7-¼, 7-½, 8, 8-¼, 8-½, 9, 9-¼, 10, 10-¼, 10-½, 11, 11-¼, 12, 12-¼, 12-½, 13, 13-¼, 13-½, 14, 14-¼, 15, 15-¼, (13mm - 24.2mm)
- EU (European) sizes: 41-76
- International sizes: 1-36

This ring sizer is missing the ring for 6 1/2, 9 1/2, 11 1/2, 12, & has TWO rings for 11 1/4. I only made whole sizes when I originally bought it so I didn't notice at first. Now that I am making rings in half sizes, I am greatly disappointed and wondering if its too late to return this item. SE JT130RS 36-Piece Metal Ring Sizer

What a disappointment but I knew better....I read the reviews prior to this purchase and found that many were claiming wrong sizing but took the chance anyway. I blame myself for believing it was a "fluke" for others but it is the manufacturer. The sizes are a mess. Mine in most cases was a 1/4 less than the marked size and it other cases 1/2 size. It made me dizzy trying to figure if I had all the sizes and just decided it was not worth it. I do not want to spend time remarking something so I have returned it. I will try to find a more accurate sizer even if it will cost more for ultimately the quality and accuracy is EVERYTHING that I am looking for. This manufacturer needs to wake up and rework this sizing for the metal used is perfect. It is not cheap at all. This is why it was hard to return--the quality of the metal is ideal and I hope I can somehow find both next time around....We shall see....

I really hesitated to buy this based on all the reviews saying the sizes weren't right. I think those reviews were probably correct. One person said the 5.25 was smaller than the 5.00. And they were indeed correct. The 5.25 is slightly smaller than the 5.00!

With that said, I just needed something that I could put around my finger so I could take a measurement with a ruler. And these work fine for that. I definitely wouldn't trust the sizes on these things without measuring them and then going to a site that gives the conversions between millimeters in diameter and actual ring sizes.

The sizes between 10-12.5 though seem to be pretty accurate. Also the millimeter designations seemed to be right on the nose for the ones I measured. (Although, it's very difficult to tell the difference between a few tenths of a millimeter)! Some people said it was very difficult to read the writing on these rings, but I found they were very clear.

I've never worn a ring before, so I had no idea what my size was. You could have told me it was 4 or 14 and I wouldn't have known the difference. I just wanted to get a ballpark idea so if I order something online, I'll only have to return it once or twice rather than 5-6 times. And for that, these will work fine. But seriously, if you really need a completely accurate measurement, I wouldn't trust these things.