Completedworks
| RINGS | ||||||||||||||||||||||||
| UK | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| US | 1.5 | 2 | 2.5 | 3 | 3.5 | 4 | 4.5 | 4.75 | 5.25 | 5.75 | 6.25 | 7 | 7.5 | 8 | 8.5 | 9 | 9.75 | 10.25 | 10.75 | 11.25 | 11.75 | 12 | 12.5 | 12.5 |
| Inside (mm) | 12.9 | 13.3 | 13.7 | 14.1 | 14.5 | 15 | 15.3 | 15.6 | 16.2 | 16.6 | 16.9 | 17.2 | 17.8 | 18.1 | 18.5 | 19.1 | 19.4 | 19.6 | 20 | 20.4 | 20.8 | 21.2 | 21.6 | 21.8 |