Measure the inside diameter of a ring that fits your intended finger. Do not include the band. These measurements are approximate; a professional fitting can help if you are unsure.
| US size | Inside diameter |
|---|---|
| 2 | 13.21 mm |
| 3 | 14.05 mm |
| 4 | 14.86 mm |
| 5 | 15.70 mm |
| 6 | 16.51 mm |
| 7 | 17.35 mm |
| 8 | 18.19 mm |
| 9 | 18.89 mm |
| 10 | 19.84 mm |
| 11 | 20.68 mm |
| 12 | 21.49 mm |
| 13 | 22.33 mm |
| 14 | 23.16 mm |