Ring Size Conversion Chart
| Inside Circumference (mm) | Inside Diameter (mm) | UK | US |
| 47 | 15.1 | I | 4 1/4 |
| 49 | 15.4 | J | 4 5/8 |
| 50 | 15.8 | K | 5 1/8 |
| 51 | 16.1 | L | 5 1/2 |
| 53 | 16.5 | M | 6 |
| 54 | 16.9 | N | 6 1/2 |
| 55 | 17.3 | O | 7 |
| 57 | 17.6 | P | 7 1/2 |
| 58 | 18 | Q | 8 |
| 59 | 18.4 | R | 8 5/8 |
| 60 | 18.9 | S | 9 1/8 |
| 62 | 19.2 | T | 9 5/8 |
| 63 | 19.6 | U | 10 1/4 |
| 64 | 19.9 | V | 10 5/8 |
| 66 | 20.3 | W | 11 1/8 |