Swiss / IT / ES to UK / AU ring size
The short answer
By the formula, Swiss / IT / ES 17 is UK / AU P 1/2.
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.
| Swiss / IT / ES | UK / AU |
|---|---|
| 4 | F |
| 5 | G |
| 6 | H |
| 7 | H 1/2 |
| 8 | I 1/2 |
| 9 | J |
| 10 | K |
| 11 | L |
| 12 | L 1/2 |
| 13 | M 1/2 |
| 14 | N |
| 15 | O |
| 16 | P |
| 17 | P 1/2 |
| 18 | Q 1/2 |
| 19 | R |
| 20 | S |
| 21 | T |
| 22 | T 1/2 |
| 23 | U 1/2 |
| 24 | V |
| 25 | W |
| 26 | X |
| 27 | X 1/2 |
| 28 | Y 1/2 |
| 29 | Z |