Ring Size Guide
Typically, rings should be made to a standard size, however you will find that many ring size guides differ – how confusing!
At Ring Supplies our rings are made to the standard USA sizes, we then provide a guide as to the nearest UK size (There is not always an exact match).
We recommend using a ring sizer mandrel with both UK & USA sizes.
Below you will find a ring size guide which also shows the inside diameter of our rings which should be used for a more accurate measurement.
US size | Inside Diameter | Approx UK size |
3 | 14.0mm | F |
3.5 | 14.4mm | G |
4 | 14.8mm | H |
4.5 | 15.2mm | I |
5 | 15.6mm | J 1/2 |
5.5 | 16.0mm | K 1/2 |
6 | 16.5mm | L 1/2 |
6.5 | 16.9mm | M 1/2 |
6.75 | 17.1mm | N |
7 | 17.3mm | O |
7.5 | 17.7mm | P |
8 | 18.1mm | Q |
8.5 | 18.5mm | R |
9 | 18.9mm | S |
9.5 | 19.4mm | S 3/4 |
10 | 19.8mm | T 1/2 |
10.5 | 20.2mm | U 1/2 |
11 | 20.6mm | V 1/2 |
11.5 | 21.0mm | W 1/2 |
12 | 21.4mm | Y |
12.5 | 21.8mm | Z |
13 | 22.2mm | Z +1 |
13.5 | 22.6mm | Z +2 |
14 | 23.0mm | Z +3 |
14.5 | 23.4mm | Z +4 |
15 | 23.8mm | Z +5 |
15.5 | 24.2mm | Z +6 |
16 | 24.6mm | Z +7 |