Ring Sizes Around ISO 68
| US | UK | ISO / EU | JP / KR | Diameter (mm) | Circumference (mm) |
| 11 | V | 65 | 24 | 20.6 | 64.6 |
| 11.5 | W | 66 | 25 | 21 | 65.9 |
| 12 | X | 67 | 26 | 21.4 | 67.2 |
| 12.5 | Y | 68 | 27 | 21.8 | 68.5 |
| 13 | Z | 70 | 28 | 22.2 | 69.7 |
| 13.5 | Z1 | 71 | 28+ | 22.6 | 71 |
| 14 | Z2 | 72 | 28+ | 23 | 72.3 |
Frequently Asked Questions
Does ISO 68 round up or down in US?
Round up on a wide band; at this size the difference a broad ring makes is a full half size, and that allowance cannot be recovered after casting.
See a number that looks off? Report an error on this page.