Size Guide
| Ring Diameter (mm) | UK | US/Canada | France | Germany | Japan | Switzerland |
|---|---|---|---|---|---|---|
| 15.6 mm | J½ | 5 | 49 | 15¾ | 9 | 9½ |
| 16.0 mm | L | 5½ | 50¾ | 16 | 10½ | 10¾ |
| 16.5 mm | M | 6 | 51½ | 16½ | 12 | 12¾ |
| 16.9 mm | N | 6½ | 52¾ | 17 | 13 | 14 |
| 17.3 mm | O | 7 | 54 | 17¼ | 14 | 15¼ |
| 17.7 mm | P | 7½ | 55¾ | 17¾ | 15 | 16½ |
| 18.2 mm | Q | 8 | 56¾ | 18 | 16 | 17¾ |
| 18.6 mm | Q½ | 8½ | 58 | 18½ | 17 | 18½ |
