Ring Size
Not sure of your size? Use our complete ring size guide to measure at home and convert between international standards.
| Inner Circumference (mm) | Inner Diameter (mm) | India | U.S.A. & Canada | U.K. / Australia / Ireland | Europe (ISO) | Japan / China |
|---|---|---|---|---|---|---|
| 48 | 15.27 | 8 | 4 1/2 | I | 48 | 8 |
| 49 | 15.70 | 9 | 5 | J 1/2 | 49 | 9 |
| 51 | 16.10 | 11 | 5 1/2 | K 1/2 | 51 | 10 |
| 52 | 16.51 | 12 | 6 | L 1/2 | 52 | 11 |
| 53 | 16.92 | 13 | 6 1/2 | M 1/2 | 53 | 13 |
| 55 | 17.35 | 14 | 7 | N 1/2 | 55 | 14 |
| 56 | 17.75 | 15 | 7 1/2 | O 1/2 | 56 | 15 |
| 57 | 18.19 | 16 | 8 | P 1/2 | 57 | 16 |
| 58 | 18.53 | 17 | 8 1/2 | Q 1/2 | 58 | 17 |
| 59 | 18.89 | 18 | 9 | R 1/2 | 59 | 18 |
| 61 | 19.41 | 19 | 9 1/2 | S 1/2 | 61 | 19 |
| 62 | 19.84 | 20 | 10 | T 1/2 | 62 | 20 |
| 63 | 20.20 | 22 | 10 1/2 | U 1/2 | 63 | 22 |
| 65 | 20.68 | 23 | 11 | V 1/2 | 65 | 23 |
| 66 | 21.08 | 24 | 11 1/2 | W 1/2 | 66 | 24 |
| 68 | 21.49 | 25 | 12 | X 1/2 | 68 | 25 |
| 69 | 21.89 | 26 | 12 1/2 | Z | 69 | 26 |
| 70 | 22.33 | 27 | 13 | Z 1/2 | 70 | 27 |
India is highlighted as our default standard. U.S.A. & Canada share a system, as do the U.K., Australia & Ireland, and Japan & China. The Europe (ISO) size equals the inner circumference in millimetres — which is why those two columns match.