Infinity Jewelry Ring Size Guide
This chart provides a comparison of U.S., U.K., and European (EU) ring sizes along with their corresponding inside diameter measurements in millimeters (mm). Use this guide to find the correct ring size for different regions.
Measuring Your Ring Size
- Use a flexible measuring tape or string to wrap around your finger
- Mark the point where the string overlaps and measure its length
- Compare this measurement with the inside diameter column to find your correct size
Tip: Always measure your finger at room temperature, as finger size can fluctuate due to temperature.
Note: Ring sizes can vary slightly based on ring style and manufacturer specifications. For precise sizing, consult a professional jeweler.
| US Size | UK Size | EU Size | Inside Diameter |
| 1 | A | 37.5 | 12.37 mm |
| 1.5 | B | 38.75 | 12.78 mm |
| 2 | B 1/2 | 40 | 13.21 mm |
| 2.5 | C 1/2 | 41.5 | 13.61 mm |
| 3 | D | 42.5 | 14.05 mm |
| 3.5 | E | 44 | 14.45 mm |
| 4 | F | 45.5 | 14.86 mm |
| 4.5 | G | 46.5 | 15.27 mm |
| 5 | H | 47.5 | 15.70 mm |
| 5.5 | J | 49 | 16.10 mm |
| 6 | K | 50.5 | 16.51 mm |
| 6.5 | L | 52 | 16.92 mm |
| 7 | M | 53.5 | 17.35 mm |
| 7.5 | N | 55 | 17.75 mm |
| 8 | O | 56 | 18.19 mm |
| 8.5 | P | 57.5 | 18.53 mm |
| 9 | Q | 59 | 18.89 mm |
| 9.5 | R | 60.25 | 19.41 mm |
| 10 | S | 61.5 | 19.84 mm |
| 10.5 | T | 62.75 | 20.20 mm |
| 11 | U | 64 | 20.68 mm |
| 11.5 | V | 65.25 | 21.08 mm |
| 12 | W | 66.5 | 21.49 mm |
| 12.5 | X | 67.75 | 21.89 mm |
| 13 | Y | 69 | 22.33 mm |
| 13.5 | Z | 70.25 | 22.75 mm |
| 14 | Z+1 | 71.5 | 23.18 mm |
| 14.5 | Z+2 | 72.75 | 23.60 mm |
| 15 | Z+3 | 74 | 24.00 mm |