Ring Size
The best way to ensure an accurate ring measurement is to visit your local jeweller, who will likely offer the service free of charge. Always measure as close to the knuckle as possible, and bear in mind that a person's ring size can change throughout the day and over time. When fingers are cold they tend to contract, and ring size may become smaller. The ideal time to measure ring size is towards the end of the day when fingers are at their thickest.
Establishing Your Ring Size
Ring size does not follow an international standard and can be confusing; for example, in the US sizes are denoted by numbers, while the UK uses letters. This conversion table will help you choose the correct size ring wherever you are in the world.
| Inter- Diameter (mm) | HK | USA | UK | JP | Swiss |
|---|---|---|---|---|---|
| 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 | 14.5 |
| 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 | 21 | 9.25 | S | 18 | 20 |
| 19.4 | 22 | 9.5 | S 1/2 | 19 | 20.75 |
| 19.8 | 23 | 10 | T 1/2 | 20 | 21.75 |
| 20.2 | 24 | 10.5 | U 1/2 | 22 | 22.75 |
| 20.6 | 25 | 11 | V 1/2 | 23 | 24.75 |
| 21 | 26 | 11.5 | W 1/2 | 24 | 26.25 |
| 21.2 | 27 | 12 | X | 24.5 | 26.25 |
| 21.6 | 28 | 12.25 | Y | 25.5 | 28 |
| 22 | 29 | 12.5 | Z 1/2 | 26.5 | 29 |
