I'm using EU sizes so please use this table to convert
from UK or US sizes or from the measurements in mm in case you
have those. Having a precise size for any ring is very important!
| EU |
USA |
UK |
Circumference |
Diameter |
| 10 | 5 1/4 | K | 50 mm | 15.92 mm |
| 11 | 5 3/4 | L | 51 mm | 16.23 mm |
| 12 | 6 | M | 52 mm | 16.55 mm |
| 13 | 6 1/2 | N | 53 mm | 16.87 mm |
| 14 | 7 | O | 54 mm | 17.19 mm |
| 15 | 7 1/2 | P | 55 mm | 17.51 mm |
| 16 | 7 3/4 | P 1/2 | 56 mm | 17.83 mm |
| 17 | 8 1/4 | P 1/2 | 57 mm | 18.14 mm |
| 18 | 8 1/2 | Q 1/2 | 58 mm | 18.46 mm |
| 19 | 8 7/8 | R | 59 mm | 18.78 mm |
| 20 | 9 1/8 | S | 60 mm | 19.10 mm |
| 21 | 9 3/4 | S 1/2 | 61 mm | 19.42 mm |
| 22 | 10 | T 1/2 | 62 mm | 19.74 mm |
| 23 | 10 1/2 | U 1/2 | 63 mm | 20.05 mm |
