A ring size is one number: the inside circumference of the band, in millimetres. Everything else — the number we ask for, the British letter, the European size — is a different way of writing that same measurement down.
Asi8 asks for a number between 4.5 and 10, in half steps. That is the scale in the dropdown on every ring page. If you know your British letter, it converts directly: J = 4.5, M = 6, O = 7, Q = 8, S = 9, U = 10. To measure at home, wrap a strip of paper around the base of your finger, mark where it overlaps, and measure the length in millimetres — that length is your circumference. Measure warm, at the end of the day, three times.
The conversion
Our rings run 4.5 to 10, which covers most adult hands. The first column is what you choose at checkout.
| Asi8 size | Circumference | Inside ø | UK | EU |
|---|---|---|---|---|
| 4.5 | 48.0 mm | 15.3 mm | J | 48 |
| 5 | 49.3 mm | 15.7 mm | K | 49 |
| 5.5 | 50.6 mm | 16.1 mm | L | 50 |
| 6 | 51.9 mm | 16.5 mm | M | 52 |
| 6.5 | 53.1 mm | 16.9 mm | N | 53 |
| 7 | 54.4 mm | 17.3 mm | O | 54 |
| 7.5 | 55.7 mm | 17.7 mm | P | 56 |
| 8 | 57.0 mm | 18.1 mm | Q | 57 |
| 8.5 | 58.3 mm | 18.5 mm | R | 58 |
| 9 | 59.5 mm | 18.9 mm | S | 60 |
| 9.5 | 60.8 mm | 19.4 mm | T | 61 |
| 10 | 62.1 mm | 19.8 mm | U | 62 |
Two ways to measure at home
Method one — the paper strip
- Cut a strip of paper about 5 mm wide and 100 mm long. Paper, not string — string stretches.
- Wrap it around the base of the finger, snug but not tight. It must be able to pass over the knuckle.
- Mark where the end overlaps, with a pen, while it is still on your finger.
- Unwrap and measure from the end of the strip to the mark, in millimetres.
- That measurement is your inside circumference. Find it in the table above and take the number in the first column.
Method two — a ring you already own
- Take a ring that fits the same finger comfortably.
- Measure straight across the inside, edge to edge, at the widest point. That is the inside diameter.
- Find that diameter in the table.
If you land between two sizes, go up. A ring slightly loose can be worn; a ring that will not pass the knuckle cannot.
Three mistakes that cause almost every resize
Measuring cold. Fingers can change by a full size between cold morning hands and warm evening ones. Measure at the end of the day, in a warm room.
Ignoring the knuckle. If your knuckle is much wider than the base of the finger, size to the knuckle, then expect a little movement below it.
Assuming both hands match. The dominant hand is usually half a size to a full size larger. Measure the finger the ring is actually for.
Wide bands need more room
A band wider than about 6 mm sits against more of the finger and feels tighter than a narrow one of the same nominal size. For a wide band, go up half a size. Our statement rings are the ones to watch — a long ring like Gathered Force runs roughly 43 mm along the finger.
Rings that need no size at all
Some of our pieces have an open or adjustable band. They arrive fitting a range rather than a point, and there is no size to choose — the product page will say so. Sets that contain no ring, like Blue Trace, never ask for one.
Frequently asked
What ring size does Asi8 ask for?
A number between 4.5 and 10, in half steps — the scale shown in the dropdown on every ring page. It matches the conventional US scale.
What is UK ring size M in the Asi8 scale?
UK M is size 6: an inside circumference of 51.9 mm and an inside diameter of 16.5 mm.
How do I measure my ring size at home without a sizer?
Wrap a 5 mm-wide paper strip around the base of the finger, mark the overlap while it is on, then measure the strip in millimetres. That length is your inside circumference. Alternatively measure the inside diameter of a ring that already fits.
Should I size up or down if I am between sizes?
Up. A slightly loose ring can be worn; one that will not clear the knuckle cannot. For bands wider than about 6 mm, go up half a size regardless.
Does the time of day affect ring size?
Yes. Fingers swell with heat, salt, exercise and the time of day, and can vary by a full size. Measure warm, in the evening, and measure three times.
Can an Asi8 ring be resized?
Every piece is made after you order it, so the size is cut for you at the point of making. Choose it at checkout. See Size & Fit and Returns & Refunds for what happens if it still is not right.
Millimetre values match the Size & Fit table on this site and the sizer in the dropdown. UK and European equivalents are the conventional trade conversions, rounded to the nearest half size. If your measurement falls exactly between two rows, take the larger.