US to JP clothing size
The short answer
By the formula, US 10 is JP 13.
UK and AU are the US number plus 4; FR is DE plus 2, and IT is FR plus 4. A tag that only says EU is usually the FR or the DE number.
| US | JP |
|---|---|
| 00 | 1 |
| 0 | 3 |
| 2 | 5 |
| 4 | 7 |
| 6 | 9 |
| 8 | 11 |
| 10 | 13 |
| 12 | 15 |
| 14 | 17 |
| 16 | 19 |
| 18 | 21 |
| 20 | 23 |