Enter either the circumference or the diameter of your finger (or an existing ring) in millimetres, and we'll convert it into the equivalent UK, US and EU ring size.
| UK | US | EU | Circumference (mm) | Diameter (mm) |
|---|---|---|---|---|
| F | 3 | 44 | 44.0 | 14.0 |
| G | 3.5 | 45 | 45.0 | 14.3 |
| H | 4 | 46 | 46.5 | 14.8 |
| I | 4.5 | 47 | 47.5 | 15.1 |
| J | 5 | 49 | 48.5 | 15.4 |
| K | 5.5 | 50 | 49.5 | 15.8 |
| L | 6 | 51 | 50.5 | 16.1 |
| M | 6.5 | 52 | 52.0 | 16.6 |
| N | 7 | 54 | 53.0 | 16.9 |
| O | 7.5 | 55 | 54.0 | 17.2 |
| P | 8 | 56 | 55.3 | 17.6 |
| Q | 8.5 | 57 | 56.3 | 17.9 |
| R | 9 | 59 | 57.8 | 18.4 |
| S | 9.5 | 60 | 58.9 | 18.8 |
| T | 10 | 61 | 60.0 | 19.1 |
| U | 10.5 | 62 | 61.2 | 19.5 |
| V | 11 | 64 | 62.4 | 19.9 |
| W | 11.5 | 65 | 63.5 | 20.2 |
| X | 12 | 66 | 64.6 | 20.6 |
Two Ways to Measure at Home
- String or paper method: wrap a strip of paper or a piece of string snugly around the base of your finger, mark where it overlaps, then measure that length against a ruler — that's your circumference in mm.
- Existing ring method: measure the inside diameter of a ring that already fits well, in millimetres, and use the "Diameter" toggle above instead.
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