EU / ISO to Swiss / IT / ES ring size
The short answer
By the formula, EU / ISO 57 is Swiss / IT / ES 17.
Inner circumference 57 mm. Ring sizes are defined by that one measurement, so this conversion is exact up to rounding: US sizes are rounded to the nearest quarter, UK letters to the nearest half.
| EU / ISO | Swiss / IT / ES |
|---|---|
| 44 | 4 |
| 45 | 5 |
| 46 | 6 |
| 47 | 7 |
| 48 | 8 |
| 49 | 9 |
| 50 | 10 |
| 51 | 11 |
| 52 | 12 |
| 53 | 13 |
| 54 | 14 |
| 55 | 15 |
| 56 | 16 |
| 57 | 17 |
| 58 | 18 |
| 59 | 19 |
| 60 | 20 |
| 61 | 21 |
| 62 | 22 |
| 63 | 23 |
| 64 | 24 |
| 65 | 25 |
| 66 | 26 |
| 67 | 27 |
| 68 | 28 |
| 69 | 29 |
| 70 | 30 |