WILLS JEWELLERY uses Hong Kong's size measurement system. You can find the size that suits you according to the following size comparison table.
| Inner ring diameter (mm) |
Hong Kong circle | American circle | british circle | Japanese circle | Swiss circle |
|---|---|---|---|---|---|
| 14.1 | 6 | 3 | F | 4 | 4 |
| 14.3 | 7 | 3.25 | F 1/2 | 5 | 5.25 |
| 14.7 | 8 | 3.75 | G | 6 | 6.5 |
| 14.9 | 9 | 4 | H | 7 | 7 |
| 15.3 | 10 | 4.5 | I | 8 | 8.5 |
| 15.7 | 11 | 5 | J 1/2 | 9 | 9.5 |
| 16.1 | 12 | 5.5 | K 1/2 | 10 | 10.5 |
| 16.5 | 13 | 6 | L 1/2 | 11 | 12.75 |
| 16.7 | 14 | 6.25 | M | 12 | 13.5 |
| 17.1 | 15 | 6.75 | N | 13.5 | 14.5 |
| 17.3 | 16 | 7 | N 1/2 | 14 | 15.25 |
| 17.7 | 17 | 7.5 | O 1/2 | 15 | 16.5 |
| 18.2 | 18 | 8 | P 1/2 | 16.25 | 18.25 |
| 18.5 | 19 | 8.5 | Q 1/2 | 17 | 18.75 |
| 18.8 | 20 | 9.75 | R | 17.5 | 19 |
| 19.1 | twenty one | 9.25 | S | 18 | 20 |
| 19.4 | twenty two | 9.5 | S 1/2 | 19 | 20.75 |
| 19.8 | twenty three | 10 | T 1/2 | 20 | 21.75 |
| 20.2 | twenty four | 10.5 | U 1/2 | twenty two | 22.75 |
| 20.6 | 25 | 11 | V 1/2 | twenty three | 24.75 |
| 21.0 | 26 | 11.5 | W 1/2 | twenty four | 26.25 |
| 21.2 | 27 | 12 | X | 24.5 | 26.75 |
| 21.6 | 28 | 12.25 | Y | 25.5 | 28 |
| 22.0 | 29 | 12.5 | Z 1/2 | 26.5 | 29 |
