Guidance / Sizing
UK letter sizes, with the millimetres behind them.
Last updated 12 August 2026 · Governing law: England and Wales
The chart
Our signets and bands are stocked from N to Z, which covers the great majority of men’s sizes. Inner diameter is derived from the circumference, so use whichever you can measure.
| UK size | Inner circumference | Inner diameter |
|---|---|---|
| N | 53.8 mm | 17.1 mm |
| O | 55.1 mm | 17.5 mm |
| P | 56.3 mm | 17.9 mm |
| Q | 57.6 mm | 18.3 mm |
| R | 58.9 mm | 18.7 mm |
| S | 60.2 mm | 19.2 mm |
| T | 61.4 mm | 19.5 mm |
| U | 62.7 mm | 20.0 mm |
| V | 64.0 mm | 20.4 mm |
| W | 65.3 mm | 20.8 mm |
| X | 66.6 mm | 21.2 mm |
| Y | 67.8 mm | 21.6 mm |
| Z | 69.1 mm | 22.0 mm |
How to measure
From a ring that already fits
- Lay the ring on a ruler and measure the inside diameter at its widest, in millimetres.
- Find that figure in the inner diameter column above.
- If it falls between two sizes, take the larger. A ring slightly loose can be worn; a ring too small cannot.
From the finger
- Wrap a strip of paper about 5 mm wide around the base of the finger, snug but not tight.
- Mark where it overlaps and measure the length to the mark.
- That length is the inner circumference. Read the letter from the chart.
- Measure at the end of the day and at room temperature. Fingers are measurably smaller when cold and in the morning.
Which finger, and how tight
A signet is conventionally worn on the little finger of the non-dominant hand, though nothing obliges you to. A plain band is worn wherever you choose.
The ring should pass the knuckle with a little resistance and sit without spinning freely. A wider band feels tighter than a narrow one at the same size — if you are moving from a 4 mm to a 6 mm band, consider going up half a size. We stock whole letters only, so where that matters, tell us and we will advise.
Resizing and exchanges
- Unengraved rings. If the size is wrong, cancel within 14 days under the ordinary right to cancel and order the correct one. That is faster and cheaper than resizing.
- Engraved rings. These are excluded from the right to cancel, so size matters more. If you are unsure, order the ring unengraved first, check the fit, and send it back to us for engraving afterwards — we will do that at the standard engraving charge.
- Resizing as a service. We can resize plain bands by up to two letters, charged on assessment. Signets with an engraved face can usually be resized; a band with an engraving inside it usually cannot without disturbing the engraving, and we will say so before starting.
We do not describe any of these as a lifetime service or a guarantee. They are chargeable jobs, quoted when you ask. Write to support@pajewelleryuk.shop or call +44 7528 455575.