International Ring Size Conversion Chart Table
| Inside Diameter | US | UK | Germany | Spain | France | Italy | Japan |
|---|---|---|---|---|---|---|---|
| 15.6 mm | 5 | J | 49 (15.6) | 9,5 | 49.5 | 9 | 9 |
| 16.2 mm | 5.5 | K | 51 (16.2) | 10,5 | 50.5 | 10 | 10 |
| 16.6 mm | 6 | L | 52 (16.6) | 12 | 52 | 11 | 11 |
| 16.9 mm | 6.5 | M | 53 (16.9) | 13,5 | 53 | 12,5 | 13 |
| 17.2 mm | 7 | N | 54 (17.2) | 14,5 | 54.5 | 14 | 14 |
| 17.8 mm | 7.5 | O | 56 (17.8) | 16 | 55.5 | 15 | 15 |
| 18.1 mm | 8 | P | 57 (18.1) | 17 | 57 | 16 | 16 |
| 18.5 mm | 8.5 | Q | 58 (18.5) | 18,5 | 58 | 17,5 | 17 |
| 19.1 mm | 9 | R | 60 (19.1) | 20 | 59.5 | 19 | 18 |
| 19.4 mm | 9.5 | S | 61 (19.4) | 21 | 61 | 20 | 19 |
| 19.7 mm | 10 | T | 62 (19.7) | 22,5 | 62 | 21,5 | 20 |
| 20.4 mm | 10.5 | U | 64 (20.4) | 23,5 | 63.5 | 23 | 22 |
| 20.7 mm | 11 | V | 65 (20.7) | 25 | 64.5 | 24 | 23 |
| 21.0 mm | 11.5 | W | 66 (21.0) | 26 | 66 | 25 | 24 |
| 21.6 mm | 12 | X | 68 (21.6) | 27,5 | 67 | 26,5 | 25 |
| 22.0 mm | 12.5 | Y | 69 (22.0) | 29 | 68.5 | 28 | 26 |
| 22.3 mm | 13 | Z | 70 (22.3) | 30 | 69.5 | 28,5 | 27 |
