The following comprehensive guide assists in determining the perfect ring size based on global sizing standards.
| Circumference (MM) | Diameter (MM) | India | UK, Europe & Australia | United States & Canada | Japan (CNSG) | Hong Kong |
|---|---|---|---|---|---|---|
| 41.0 | 13.06 | 1 | C | 1 | — | — |
| 41.7 | 13.26 | 2 | D | 2 | 2 | — |
| 42.3 | 13.46 | — | D½ | 2¼ | — | — |
| 42.9 | 13.67 | 3 | E | 2½ | 3 | — |
| 43.6 | 13.87 | 4 | E½ | 2¾ | — | — |
| 44.2 | 14.07 | — | F | 3 | 4 | 6 |
| 44.8 | 14.27 | 5 | F½ | 3¼ | 5 | — |
| 45.5 | 14.48 | — | G | 3½ | — | 7.5 |
| 46.1 | 14.68 | 6 | G½ | 3¾ | 6 | — |
| 46.8 | 14.88 | — | H | 4 | 7 | 9 |
| 47.4 | 15.09 | 7 | H½ | 4¼ | — | — |
| 48.0 | 15.29 | 8 | I | 4½ | 8 | 10 |
| 48.7 | 15.49 | 9 | J | 4¾ | — | — |
| 49.3 | 15.70 | — | J½ | 5 | 9 | 11 |
| 50.0 | 15.90 | 10 | K | 5¼ | — | — |
| 50.6 | 16.10 | — | K½ | 5½ | 10 | 12 |
| 51.2 | 16.31 | 11 | L | 5¾ | — | — |
| 51.9 | 16.51 | 12 | L½ | 6 | 11 | 13 |
| 52.5 | 16.71 | — | M | 6¼ | 12 | — |
| 53.1 | 16.92 | 13 | M½ | 6½ | 13 | 14.5 |
| 53.8 | 17.12 | — | N | 6¾ | — | — |
| 54.4 | 17.32 | 14 | N½ | 7 | 14 | 16 |
| 55.1 | 17.53 | 15 | O | 7¼ | — | — |
| 55.7 | 17.73 | — | O½ | 7½ | 15 | 17 |
| 56.3 | 17.93 | 16 | P | 7¾ | — | — |
| 57.0 | 18.14 | 17 | P½ | 8 | 16 | 18 |
| 57.6 | 18.34 | — | Q | 8¼ | — | — |
| 58.3 | 18.54 | 18 | Q½ | 8½ | 17 | 19 |
| 58.9 | 18.75 | 19 | R | 8¾ | — | — |
| 59.5 | 18.95 | — | R½ | 9 | 18 | 20.5 |
| 60.2 | 19.15 | 20 | S | 9¼ | — | — |
| 60.8 | 19.35 | 21 | S½ | 9½ | 19 | 22 |
| 62.1 | 19.76 | 22 | T | 10 | 20 | 23 |
| 62.7 | 19.96 | 23 | U | 10¼ | 21 | — |
| 63.4 | 20.17 | — | U½ | 10½ | 22 | 24 |
| 64.0 | 20.37 | 24 | V | 10¾ | — | — |
| 64.6 | 20.57 | 25 | V½ | 11 | 23 | 25 |
| 65.3 | 20.78 | — | W | 11¼ | — | — |
| 65.9 | 20.98 | 26 | W½ | 11½ | 24 | 26 |
| 66.6 | 21.18 | — | X | 11¾ | — | — |
| 67.2 | 21.39 | 27 | X½ | 12 | 25 | 27.75 |
| 67.8 | 21.59 | 28 | Y | 12¼ | — | — |
| 68.5 | 21.79 | — | Z | 12½ | 26 | — |
| 69.1 | 22.00 | 29 | Z½ | 12¾ | — | — |
| 69.7 | 22.20 | 30 | — | 13 | 27 | 30 |
| 70.4 | 22.40 | — | Z+1 | 13¼ | — | — |
| 71.0 | 22.61 | 31 | — | 13½ | — | — |