US Size to UK Size
Convert US Size to UK Size with international size equivalence charts. Free online size converter.
Based on published international size equivalence charts.
Ring Size Calculator
Ring Size Conversion Chart
| US | UK | EU | Japan |
|---|---|---|---|
| 3 | F | 44 | 1 |
| 3.25 | F½ | 44.5 | 2 |
| 3.5 | G | 45 | 3 |
| 3.75 | G½ | 45.5 | 4 |
| 4 | H | 46 | 5 |
| 4.25 | H½ | 46.5 | 6 |
| 4.5 | I | 47 | 7 |
| 4.75 | I½ | 47.5 | 8 |
| 5 | J | 48 | 9 |
| 5.25 | J½ | 48.5 | 10 |
| 5.5 | K | 49 | 11 |
| 5.75 | K½ | 49.5 | 12 |
| 6 | L | 50 | 13 |
| 6.25 | L½ | 50.5 | 14 |
| 6.5 | M | 51 | 15 |
| 6.75 | M½ | 51.5 | 16 |
| 7 | N | 52 | 17 |
| 7.25 | N½ | 52.5 | 18 |
| 7.5 | O | 53 | 19 |
| 7.75 | O½ | 53.5 | 20 |
| 8 | P | 54 | 21 |
| 8.25 | P½ | 54.5 | 22 |
| 8.5 | Q | 55 | 23 |
| 8.75 | Q½ | 55.5 | 24 |
| 9 | R | 56 | 25 |
| 9.25 | R½ | 56.5 | 26 |
| 9.5 | S | 57 | 27 |
| 9.75 | S½ | 57.5 | 28 |
| 10 | T | 58 | 29 |
| 10.25 | T½ | 58.5 | 30 |
| 10.5 | U | 59 | 31 |
| 10.75 | U½ | 59.5 | 32 |
| 11 | V | 60 | 33 |
| 11.25 | V½ | 60.5 | 34 |
| 11.5 | W | 61 | 35 |
| 11.75 | W½ | 61.5 | 36 |
| 12 | X | 62 | 37 |
The formula
Sizes map through equivalence charts, not a single multiplier. Use the chart above to find the matching size.