Ring Size Guide
Measure your finger to find your ring size, or convert between UK, EU and US sizes.
📏 A guide for measuring at home — sizing varies, so confirm with a jeweller for a perfect fit. Free, no sign-up.
1. Wrap a thin strip of paper around the base of your finger.
2. Mark where it overlaps and measure the length in mm.
3. This is your circumference in mm — enter it below.
Ring size conversion chart
| US | UK | EU | Diameter (mm) | Circ. (mm) |
|---|---|---|---|---|
| 3 | F | 44 | 14.1 | 44.2 |
| 3.5 | G | 45 | 14.5 | 45.5 |
| 4 | H | 47 | 14.9 | 46.8 |
| 4.5 | I | 48 | 15.3 | 48.0 |
| 5 | J½ | 49¼ | 15.7 | 49.3 |
| 5.5 | L | 50½ | 16.1 | 50.6 |
| 6 | M | 51¾ | 16.5 | 51.9 |
| 6.5 | N | 53 | 16.9 | 53.1 |
| 7 | O | 54½ | 17.3 | 54.4 |
| 7.5 | P | 56 | 17.7 | 55.7 |
| 8 | Q | 57¼ | 18.1 | 57.0 |
| 8.5 | R | 58¾ | 18.5 | 58.3 |
| 9 | S | 60 | 19.0 | 59.5 |
| 9.5 | T | 61½ | 19.4 | 60.8 |
| 10 | U | 62¾ | 19.8 | 62.1 |
| 10.5 | V | 64 | 20.2 | 63.4 |
| 11 | W | 65½ | 20.6 | 64.6 |
| 12 | Y | 68 | 21.4 | 67.2 |
| 13 | Z+1 | 70¾ | 22.2 | 69.7 |
Conversions are approximate and can vary slightly between jewellers. For a perfect fit, confirm your size with a jeweller.
About the Ring Size Guide
The ring size guide finds your ring size from your finger measurement and converts between UK letter, US number and EU/mm systems.
How to use the Ring Size Guide
How to measure your ring size at home
Two methods work well. Wrap a strip of paper or string around the base of your finger, mark where it overlaps, and measure that length in millimetres — that is your finger’s circumference. Or measure the inside diameter of a ring that already fits. Measure at the end of the day when fingers are at their largest, and allow for the wider knuckle the ring has to pass over.
UK, US and EU sizes explained
The three systems describe the same band differently. UK sizes use letters (A to Z), US sizes use numbers, and EU sizes are based on the inside circumference in millimetres. Because they do not line up neatly, converting from a measurement rather than guesswork is the reliable way to move between them.