How a well-fitting ring should feel
A ring that fits sits comfortably around the base of your finger, slides over the knuckle with a gentle push, and stays in place when you relax your hand — snug enough not to slip off, loose enough to turn. It should feel natural, and you should barely notice it.
A few quick tips
- Your fingers fluctuate slightly with temperature and activity — taking two or three readings gives you a number you can feel confident about.
- If your knuckle is noticeably wider than the base of your finger, choose the size that slides comfortably over the knuckle.
- Wide-band rings sit a little more snugly than thin ones.
- If you land between two sizes, choose the larger.
Method 1 — Use a ring you already own
If you have a ring that fits the same finger well, set it on a ruler and measure the inside diameter in millimeters — the widest point across the inner circle, not counting the band itself. Match that number to the chart below.
Method 2 — Measure with a strip of paper
Cut a narrow strip of paper and wrap it snugly around the base of the finger the ring will live on, making sure it can still slide over your knuckle. Mark the point where the paper overlaps, lay it flat, and measure the length in millimeters. That is your inside circumference — match it to the chart below. Avoid string or thread, which tends to pull too tight and give a size that is too small.
For the most reliable result, ask any local jeweler for a quick, free professional sizing — or email us; we are glad to help you get it exactly right.
Ring size chart (US sizes)
| US size | Inside diameter (mm) | Inside circumference (mm) |
|---|---|---|
| 3 | 14.05 | 44.1 |
| 3.5 | 14.45 | 45.4 |
| 4 | 14.86 | 46.7 |
| 4.5 | 15.26 | 47.9 |
| 5 | 15.70 | 49.3 |
| 5.5 | 16.10 | 50.6 |
| 6 | 16.51 | 51.9 |
| 6.5 | 16.92 | 53.2 |
| 7 | 17.32 | 54.4 |
| 7.5 | 17.73 | 55.7 |
| 8 | 18.14 | 57.0 |
| 8.5 | 18.54 | 58.2 |
| 9 | 18.95 | 59.5 |
| 9.5 | 19.35 | 60.8 |
| 10 | 19.76 | 62.1 |
If you are between two sizes, we recommend choosing the larger.
Made to your exact size
Every Allen Moreau ring is made to order in your precise US size. Because personalized and made-to-order rings are final sale, please double-check your measurement before ordering. If you are unsure at all, email us a photo of how you measured and we will confirm the size with you.