Finding your ring size
UK ring sizes run from A (smallest) to Z+ in half-size steps. Our listings give the UK size, with the US equivalent where we know it.
Measure a ring you already own
- Choose a ring that fits the intended finger well.
- Measure the inside diameter in millimetres, edge to edge.
- Match it in the table below.
| Inside diameter (mm) | UK size | US size |
|---|---|---|
| 15.7 | H | 4 |
| 16.5 | J½ | 5 |
| 17.3 | L½ | 6 |
| 18.2 | O | 7 |
| 19.0 | Q | 8 |
| 19.8 | S | 9 |
Tips
- Measure at the end of the day, when fingers are largest.
- Wide bands fit tighter — go up half a size for bands wider than 6 mm.