- Place a proper fitting ring on a ruler and measure the inside diameter of the ring (where the ring is at its widest)
- Go the conversion table below (ISO standard) and ring to find the ring size equivalent to your ring diameter. If the ring diameter is between two ring sizes, we suggest you choose the larger one
Inside Diameter (in.) | Inside Diameter (mm.) | Ring Size (ISO Standard) |
0.578 | 14.68 | 46.1 |
0.586 | 14.88 | 46.8 |
0.594 | 15.09 | 47.4 |
0.602 | 15.29 | 48.0 |
0.610 | 15.49 | 48.7 |
0.618 | 15.70 | 49.3 |
0.626 | 15.90 | 50.0 |
0.634 | 16.10 | 50.6 |
0.642 | 16.31 | 51.2 |
0.650 | 16.51 | 51.9 |
0.658 | 16.71 | 52.5 |
0.666 | 16.92 | 53.1 |
0.674 | 17.12 | 53.8 |
0.682 | 17.32 | 54.4 |
0.690 | 17.53 | 55.1 |
0.698 | 17.73 | 55.7 |
0.706 | 17.93 | 56.3 |
0.714 | 18.14 | 57.0 |
0.722 | 18.34 | 57.6 |
0.730 | 18.54 | 58.3 |
0.738 | 18.75 | 58.9 |
0.746 | 18.95 | 59.5 |
0.754 | 19.15 | 60.2 |
0.762 | 19.35 | 60.8 |
0.770 | 19.56 | 61.4 |
0.778 | 19.76 | 62.1 |
0.786 | 19.96 | 62.7 |
0.794 | 20.17 | 63.4 |
0.802 | 20.37 | 64.0 |
0.810 | 20.57 | 64.6 |
0.818 | 20.78 | 65.3 |
0.826 | 20.98 | 65.9 |
0.834 | 21.18 | 66.6 |
0.842 | 21.39 | 67.2 |
0.850 | 21.59 | 67.8 |
0.858 | 21.79 | 68.5 |
0.866 | 22.00 | 69.1 |
0.874 | 22.20 | 69.7 |
0.882 | 22.40 | 70.4 |