The short answer
Wrap a strip of paper around the base of your finger, mark where it overlaps, measure that length in millimetres, and match it to the chart below. That circumference is your ring size. It takes about two minutes and needs nothing you don't already have.
Method 1: paper or string
- Cut a strip of paper about 5 mm wide, or use a length of non-stretchy string.
- Wrap it snugly around the base of the finger — snug enough that it would not slide off over the knuckle, but not tight.
- Mark the overlap with a pen.
- Lay it flat against a ruler and read the length in millimetres.
- Find that number in the chart below.
Method 2: measure a ring you already own
Take a ring that fits the same finger and measure the inside diameter across the widest point, in millimetres. Multiply by 3.14 to get the circumference, then use the chart. Measuring the inside rather than the outside matters — a wide band can add half a millimetre or more.
US ring size chart
| US size | Inside diameter (mm) | Circumference (mm) |
|---|---|---|
| 4 | 14.9 | 46.8 |
| 5 | 15.7 | 49.3 |
| 6 | 16.5 | 51.9 |
| 7 | 17.3 | 54.4 |
| 8 | 18.1 | 57.0 |
| 9 | 18.9 | 59.5 |
| 10 | 19.8 | 62.1 |
| 11 | 20.6 | 64.6 |
| 12 | 21.4 | 67.2 |
| 13 | 22.2 | 69.7 |
Four things that change the answer
- Time of day. Fingers are smallest in the morning and largest in the evening. Measure late in the day for a fit you can wear all day.
- Temperature. Cold shrinks fingers noticeably. Don't measure straight after being outside in winter.
- Knuckle size. If your knuckle is much wider than the base of your finger, size to slide over the knuckle, then expect a little movement at the base.
- Band width. Wide bands (4 mm and up) fit tighter than thin ones. Go up a quarter to a half size for a wide band.
If you measure between two sizes
Round up. A ring that is marginally loose can be worn; one that is too tight cannot. Every piece we make is available in quarter sizes from US 3 to 13, so there is usually a size that lands exactly where you need it.
If you get it wrong
Resizing is free for life on our solid gold rings, and we pay postage both ways. Returns are free within 60 days. So an imperfect first guess costs you nothing but a few days.