EU / ISO to US / Canada ring size
The short answer
By the formula, EU / ISO 57 is US / Canada 8.
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 | US / Canada |
|---|---|
| 44 | 3 |
| 45 | 3.25 |
| 46 | 3.75 |
| 47 | 4 |
| 48 | 4.5 |
| 49 | 5 |
| 50 | 5.25 |
| 51 | 5.75 |
| 52 | 6 |
| 53 | 6.5 |
| 54 | 6.75 |
| 55 | 7.25 |
| 56 | 7.75 |
| 57 | 8 |
| 58 | 8.5 |
| 59 | 8.75 |
| 60 | 9.25 |
| 61 | 9.5 |
| 62 | 10 |
| 63 | 10.5 |
| 64 | 10.75 |
| 65 | 11.25 |
| 66 | 11.5 |
| 67 | 12 |
| 68 | 12.25 |
| 69 | 12.75 |
| 70 | 13.25 |