Conversion reference
Click any row to highlight it. EU and Italian sizes are identical — both use inner circumference in mm.
| US | EU / IT | UK | Ø mm | Circ. mm |
|---|---|---|---|---|
| 3 | 44 | F | 14.1 | 44.2 |
| 3¼ | 44½ | F½ | 14.3 | 44.8 |
| 3½ | 45½ | G | 14.5 | 45.5 |
| 3¾ | 46 | G½ | 14.6 | 46.0 |
| 4 | 46¾ | H | 14.9 | 46.8 |
| 4¼ | 47½ | H½ | 15.1 | 47.4 |
| 4½ | 48 | I | 15.3 | 48.0 |
| 4¾ | 49 | I½ | 15.6 | 49.0 |
| 5 | 49¼ | J | 15.7 | 49.3 |
| 5¼ | 50 | J½ | 15.9 | 50.0 |
| 5½ | 50½ | K | 16.1 | 50.6 |
| 5¾ | 51 | K½ | 16.3 | 51.2 |
| 6 | 52 | L | 16.5 | 51.9 |
| 6¼ | 52½ | L½ | 16.7 | 52.5 |
| 6½ | 53 | M | 16.9 | 53.1 |
| 6¾ | 53½ | M½ | 17.1 | 53.8 |
| 7 | 54½ | N | 17.3 | 54.4 |
| 7¼ | 55 | N½ | 17.5 | 55.1 |
| 7½ | 55¾ | O | 17.8 | 55.9 |
| 7¾ | 56½ | O½ | 18.0 | 56.6 |
| 8 | 57 | P | 18.2 | 57.2 |
| 8¼ | 57½ | P½ | 18.3 | 57.6 |
| 8½ | 58½ | Q | 18.6 | 58.5 |
| 8¾ | 59 | Q½ | 18.8 | 59.1 |
| 9 | 59½ | R | 19.0 | 59.7 |
| 9¼ | 60½ | R½ | 19.2 | 60.4 |
| 9½ | 61 | S | 19.4 | 61.0 |
| 9¾ | 61½ | S½ | 19.6 | 61.5 |
| 10 | 62 | T | 19.8 | 62.1 |
| 10¼ | 62½ | T½ | 19.9 | 62.5 |
| 10½ | 63½ | U | 20.2 | 63.5 |
| 10¾ | 64 | U½ | 20.4 | 64.1 |
| 11 | 64½ | V | 20.6 | 64.6 |
| 11¼ | 65½ | V½ | 20.8 | 65.3 |
| 11½ | 66 | W | 21.0 | 65.9 |
| 11¾ | 66½ | W½ | 21.1 | 66.4 |
| 12 | 67 | X | 21.3 | 66.9 |
| 12¼ | 68 | X½ | 21.6 | 67.8 |
| 12½ | 68½ | Y | 21.8 | 68.5 |
| 12¾ | 69 | Y½ | 22.0 | 69.0 |
| 13 | 69½ | Z | 22.2 | 69.7 |
All diameters and circumferences are inner measurements. Sizes assume a standard comfort-fit band; very wide bands may require sizing up ½–1 step.