By the Internal Diameter of an Existing Ring
Measure an existing ring's internal diameter as shown below:
Use the table below to determine your ring size. Orders must be given according to the U.S. / Canada size.
| Internal Diameter (mm) | U.S./Canada Size | France |
| 14.0 | 3 | 44 |
| 14.4 | 3.5 | 45.25 |
| 14.8 | 4 | 46.5 |
| 15.2 | 4.5 | 47.75 |
| 15.6 | 5 | 49 |
| 16.0 | 5.5 | 50.75 |
| 16.4 | 6 | 51.5 |
| 16.8 | 6.5 | 52.75 |
| 17.2 | 7 | 54 |
| 17.6 | 7.5 | 55.25 |
| 18.0 | 8 | 56.75 |
| 18.4 | 8.5 | 58 |
| 19.0 | 9 | 59.25 |
| 19.4 | 9.5 | 60.75 |
| 19.8 | 10 | 61.75 |