UK Size to US Size
Convert UK Size to US Size instantly with our free calculator. Essential for professionals and students. Get precise results with detailed tables and formula...
Based on published international size equivalence charts. · Updated 2026-05-29
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.