9 October 2026 · Guide
UK Ring Size Guide: How to Measure Your Finger at Home
Measure your ring size at home, and convert between UK letter sizes and the US numbers used on many rings.
The right ring size matters: too tight and it is uncomfortable, too loose and it can slip off. You can measure at home in a few minutes.
How to measure
- Cut a thin strip of paper or use a piece of string, about 10cm long.
- Wrap it around the base of the finger you want to wear the ring on.
- Mark where the paper overlaps, then lay it flat and measure the length in millimetres. That is your finger circumference.
- Match it to the chart below.
Size chart
| Circumference (mm) | UK size | US size |
|---|---|---|
| 46.5 | H½ | 4 |
| 49.3 | J½ | 5 |
| 51.8 | L½ | 6 |
| 54.4 | N½ | 7 |
| 57.0 | P½ | 8 |
| 59.5 | R½ | 9 |
| 62.1 | T½ | 10 |
Many of our rings are listed in US sizes, so use this table to convert from your UK size. If you are between sizes, go up to the larger one.
Tips for a better fit
- Measure later in the day, when fingers are at their largest, and avoid measuring when your hands are cold.
- Wide bands and bands with large stones fit more snugly, so consider a half size up.
- If your knuckle is larger than the base of your finger, measure both and choose a size in between.
- Measure on more than one day if you can; fingers change with temperature and activity.
Ready to choose? Browse our moissanite rings.
