How EU sizes work
The EU scale, based on ISO 8653, numbers each size by the ring’s inner circumference in millimetres. The inner diameter follows from it: diameter = circumference ÷ π, so size 54 has an inner diameter of about 17.2 mm.
| EU size | Inner circumference | Inner diameter |
|---|---|---|
| 44 | 44.0 mm | 14.0 mm |
| 45 | 45.0 mm | 14.3 mm |
| 46 | 46.0 mm | 14.6 mm |
| 47 | 47.0 mm | 15.0 mm |
| 48 | 48.0 mm | 15.3 mm |
| 49 | 49.0 mm | 15.6 mm |
| 50 | 50.0 mm | 15.9 mm |
| 51 | 51.0 mm | 16.2 mm |
| 52 | 52.0 mm | 16.6 mm |
| 53 | 53.0 mm | 16.9 mm |
| 54 | 54.0 mm | 17.2 mm |
| 55 | 55.0 mm | 17.5 mm |
| 56 | 56.0 mm | 17.8 mm |
| 57 | 57.0 mm | 18.1 mm |
| 58 | 58.0 mm | 18.5 mm |
| 59 | 59.0 mm | 18.8 mm |
| 60 | 60.0 mm | 19.1 mm |
| 61 | 61.0 mm | 19.4 mm |
| 62 | 62.0 mm | 19.7 mm |
| 63 | 63.0 mm | 20.1 mm |
| 64 | 64.0 mm | 20.4 mm |
| 65 | 65.0 mm | 20.7 mm |
| 66 | 66.0 mm | 21.0 mm |
| 67 | 67.0 mm | 21.3 mm |
| 68 | 68.0 mm | 21.6 mm |
| 69 | 69.0 mm | 22.0 mm |
| 70 | 70.0 mm | 22.3 mm |
Measure a ring that fits
- Choose a ring that fits comfortably on the same finger of the same hand; fingers differ.
- Measure the inside diameter at its widest point, in millimetres, with a ruler or a calliper.
- Multiply by 3.1416 to get the circumference and choose the closest size in the chart. If you’re between two sizes, choose the larger one.
Measure your finger
- Wrap a thin strip of paper around the base of the finger. It should slide over the knuckle with a little resistance.
- Mark where the strip overlaps and measure the length in millimetres: that is your circumference.
- Measure at the end of the day, when fingers are slightly larger, and repeat two or three times.
Paper and string methods can be off by a size, especially if the strip stretches or your knuckle is large. For an important piece, a jeweler’s sizing is the safest choice.
Band width and comfort
A wide band feels tighter than a narrow one at the same size. Your design’s band width is shown before you approve; for a wide band, consider one size up.
Why we don’t measure from photos
A photo of a hand, a camera estimate or an on-screen ruler can’t measure a finger precisely, so we don’t offer them. Your ring size shapes the design itself: the band’s thickness and comfort are tailored to your exact size.
Sizes we make
We make EU sizes 44 to 70. If you need a size outside this range, contact us: we’ll review it instead of extrapolating.
Questions and answers
What’s the difference between ring size and diameter?
The EU size is the inner circumference in millimetres; the inner diameter is that number divided by π. Size 52, for example, is about 16.6 mm in diameter.
Can I change the size before ordering?
Yes. Before you approve, changing the size doesn’t use a refinement round; we adapt your design to the new size and check it again.
I’m between two sizes. Which should I choose?
Usually the larger one, especially for wide bands. A ring that’s slightly loose is more comfortable than one that won’t pass the knuckle.
Spotted something inaccurate? Tell us through our contact page. Contact