Ring sizing gauges and finger gauges as well as published charts do not always agree. Add to this that there are two conflicting methods of reading ring gauges so it is quite common for ring sizes to vary slightly from one workshop or jeweler to another. The ring sizing information presented here is the result of a conscientious study and comparison of various sources and is consistent with the instruments and measuring technique that we use in our workshop.
| Inside | Inside | Inside | Inside | Number Sizes |
|---|---|---|---|---|
| Diameter | Diameter | Circumference | Circumeference | US / CANADA |
| (inches) | (mm) | (inches) | (mm) | Standard |
| 0.618 | 15.7 | 1.941 | 49.30 | 5 |
| 0.634 | 16.1 | 1.991 | 50.60 | 5.5 |
| 0.65 | 16.5 | 2.041 | 51.8 | 6 |
| 0.666 | 16.9 | 2.091 | 53.1 | 6.5 |
| 0.682 | 17.3 | 2.141 | 54.4 | 7 |
| 0.698 | 17.7 | 2.192 | 55.7 | 7.5 |
| 0.714 | 18.1 | 2.242 | 56.9 | 8 |
| 0.73 | 18.5 | 2.292 | 58.5 | 8.5 |
| 0.746 | 18.9 | 2.342 | 59.2 | 9 |
| 0.762 | 19.4 | 2.393 | 60.8 | 9.5 |
| 0.778 | 19.8 | 2.443 | 62.1 | 10 |
| 0.794 | 20.2 | 2.493 | 63.3 | 10.5 |
| 0.810 | 20.6 | 2.543 | 64.6 | 11 |
| 0.826 | 21 | 2.594 | 65.9 | 11.5 |
| 0.842 | 21.4 | 2.644 | 67.2 | 12 |
| 0.858 | 21.8 | 2.694 | 68.4 | 12.5 |
| 0.874 | 22.2 | 2.744 | 69.7 | 13 |
| 0.89 | 22.6 | 2.795 | 71 | 13.5 |
| 0.906 | 23 | 2.845 | 72.3 | 14 |
| 0.922 | 23.4 | 2.895 | 73.5 | 14.5 |