SIZE GUIDE
SIZE GUIDE
The standards for ring sizes differ between Japanese ring sizes and American/European ring sizes.
The actual size will vary slightly depending on the thickness of the ring, the design, and the roundness of the inside.
Also, since the Japanese size is used as a standard, there may be a slight difference.
| Insidediameter (mm) |
Circumference (mm) |
United States | Europe | Japan |
|---|---|---|---|---|
| 13 | 40.8 | 1 | C | 1 |
| 13 1/3 | 41.9 | 2 | D | 2 |
| 13 2/3 | 42.9 | 2.5 | Ｅ | 3 |
| 14 | 44.0 | 3 | Ｆ | 4 |
| 14 1/3 | 45.0 | 3.5 | Ｇ | 5 |
| 14 2/3 | 46.1 | 3.5 - 4 | Ｇ - Ｈ | 6 |
| 15 | 47.1 | 4 - 4.5 | Ｈ - Ｉ | 7 |
| 15 1/3 | 48.2 | 4.5 - 5 | Ｉ - Ｊ | 8 |
| 15 2/3 | 49.2 | 5 | Ｊ | 9 |
| 16 | 50.3 | 5.5 | Ｋ | 10 |
| 16 1/3 | 51.3 | 6 | Ｌ | 11 |
| 16 2/3 | 52.4 | 6.5 | Ｌ - Ｍ | 12 |
| 17 | 53.4 | 6.5 - 7 | Ｍ - Ｎ | 13 |
| 17 1/3 | 54.5 | 7 - 7.5 | Ｎ - Ｏ | 14 |
| 17 2/3 | 55.5 | 7.5 - 8 | Ｏ - Ｐ | 15 |
| 18 | 56.6 | 8 | Ｐ | 16 |
| 18 1/3 | 57.6 | 8.5 | Ｑ | 17 |
| 18 2/3 | 58.6 | 9 | Ｒ | 18 |
| 19 | 59.7 | 9.5 | Ｓ | 19 |
| 19 1/3 | 60.7 | 10 | Ｔ | 20 |
| 19 2/3 | 61.8 | 10 - 10.5 | Ｔ - Ｕ | 21 |
| 20 | 62.8 | 10.5 | Ｕ | 22 |
| 20 1/3 | 63.9 | 11 | Ｖ | 23 |
| 20 2/3 | 64.9 | 11.5 | Ｗ | 24 |
| 21 | 66.0 | 12 | Ｘ | 25 |
| 21 1/3 | 67.0 | 12.5 | Ｙ | 26 |
| 21 2/3 | 68.0 | 13 | Ｚ | 27 |