​All sizes are US RING SIZE.
Rings are generally measured using the diameter, the easiest way to determine this is by measuring a ring you already own.

Please keep in mind the width of the ring you are ordering. The wider the ring is, the larger the size should be for it to fit as you would expect since it is harder to put on. For example, your size on a 4 mm and 17 mm rings would not be the same. The 4 mm would be your exact ring size if measured by a jeweler (or a ring measuring tool) and the 17 mm would probably be an entire size up.

5           15.5 mm
6           16.5 mm
7            17.0 mm
8            18.0 mm
9            19.0 mm
10          20.0 mm
11          20.5 mm
12          21.5 mm
13          22.5 mm
​
​All sizes are US RING SIZE