What Is a Ring Size?
A ring size represents the inside measurement of a ring. In the United States, ring sizes are shown as numbers, such as size 5, 6, 7, or 8.
Ring sizing may be based on:
- The inner diameter of a ring
- The inner circumference of a ring
- The measurement around your finger
Different countries use different sizing systems, so always check whether the chart displays US, UK, European, or international ring sizes.
US Ring Size Chart
Use the chart below to compare US ring sizes with their corresponding inside diameter and circumference measurements in millimeters and inches.
| US Size | Inside Diameter | Inside Circumference | Diameter (in) | Circumference (in) |
|---|---|---|---|---|
| 3 | 14.1 mm | 44.2 mm | 0.554 | 1.740 |
| 3.5 | 14.5 mm | 45.5 mm | 0.570 | 1.791 |
| 4 | 14.9 mm | 46.8 mm | 0.586 | 1.843 |
| 4.5 | 15.3 mm | 48.0 mm | 0.602 | 1.890 |
| 5 | 15.7 mm | 49.3 mm | 0.618 | 1.941 |
| 5.5 | 16.1 mm | 50.6 mm | 0.634 | 1.992 |
| 6 | 16.5 mm | 51.9 mm | 0.650 | 2.043 |
| 6.5 | 16.9 mm | 53.1 mm | 0.665 | 2.091 |
| 7 | 17.3 mm | 54.4 mm | 0.682 | 2.142 |
| 7.5 | 17.7 mm | 55.7 mm | 0.698 | 2.193 |
| 8 | 18.1 mm | 57.0 mm | 0.714 | 2.244 |
| 8.5 | 18.6 mm | 58.3 mm | 0.731 | 2.295 |
| 9 | 18.9 mm | 59.5 mm | 0.746 | 2.343 |
| 9.5 | 19.4 mm | 60.8 mm | 0.762 | 2.394 |
| 10 | 19.8 mm | 62.1 mm | 0.778 | 2.445 |
| 10.5 | 20.2 mm | 63.4 mm | 0.795 | 2.496 |
| 11 | 20.6 mm | 64.6 mm | 0.810 | 2.543 |
| 11.5 | 21.0 mm | 65.9 mm | 0.826 | 2.594 |
| 12 | 21.4 mm | 67.2 mm | 0.842 | 2.646 |
| 12.5 | 21.8 mm | 68.5 mm | 0.858 | 2.697 |
| 13 | 22.2 mm | 69.7 mm | 0.873 | 2.744 |
Printable Ring Size Chart
Use the Mivaan printable ring size chart for a convenient visual size reference. The downloadable PDF can help you compare a well-fitting ring with standard US ring sizes.
For accurate printing, select Actual Size or 100% Scale in your printer settings. Do not use the “Fit to Page” option, as it may change the size of the chart.