Ring Size Comparison Table
| USA | U.K | Diameter (mm) | Circumference (mm) |
| 6 | M | 16.40 | 52.00 |
| 7 | O | 17.30 | 54.50 |
| 8 | Q | 18.10 | 57.00 |
| 9 | S | 18.90 | 59.50 |
| 10 | T 1/2 | 19.70 | 62.00 |
| 11 | V 1/2 | 20.60 | 64.50 |
| 12 | Y | 21.40 | 67.50 |
| USA | U.K | Diameter (mm) | Circumference (mm) |
| 6 | M | 16.40 | 52.00 |
| 7 | O | 17.30 | 54.50 |
| 8 | Q | 18.10 | 57.00 |
| 9 | S | 18.90 | 59.50 |
| 10 | T 1/2 | 19.70 | 62.00 |
| 11 | V 1/2 | 20.60 | 64.50 |
| 12 | Y | 21.40 | 67.50 |