01 / A USEFUL STARTING POINT
How to measure
your ring size.
A professional jeweler can measure your finger directly. If you are starting at home, use a ring that fits the same finger comfortably, or take a careful finger measurement.
- With a ring you own. Measure its inside diameter, edge to edge through the center, in millimeters. Do not include the metal. Compare that measurement with the reference below.
- With a finger measurement. Wrap a flexible tape or non-stretch strip of paper around the base of the finger. Mark where it meets and measure the length in millimeters. This gives an approximate circumference.
- Check the fit. The ring must pass over the knuckle and sit comfortably at the base. If the measurements disagree or fall between sizes, ask for help rather than assuming the closest number will fit.
Home measurements are a starting point. Band width, finger shape and the actual design affect the final fit.
02 / THE US SIZE REFERENCE
A number to begin with.
Approximate US ring measurements, in millimeters. These are sizing references, not a list of sizes in stock.
| US size | Inside diameter | Circumference |
|---|---|---|
| 4 | 14.9 mm | 46.8 mm |
| 4.5 | 15.3 mm | 48.0 mm |
| 5 | 15.7 mm | 49.3 mm |
| 5.5 | 16.1 mm | 50.6 mm |
| 6 | 16.5 mm | 51.9 mm |
| 6.5 | 16.9 mm | 53.1 mm |
| 7 | 17.3 mm | 54.4 mm |
| 7.5 | 17.7 mm | 55.7 mm |
| 8 | 18.1 mm | 57.0 mm |
| 8.5 | 18.5 mm | 58.3 mm |
| 9 | 18.9 mm | 59.5 mm |
| 9.5 | 19.4 mm | 60.8 mm |
| 10 | 19.8 mm | 62.1 mm |
| 10.5 | 20.2 mm | 63.4 mm |
| 11 | 20.6 mm | 64.6 mm |
| 11.5 | 21.0 mm | 65.9 mm |
| 12 | 21.4 mm | 67.2 mm |
No printed or on-screen circle is used as an exact measuring tool. Screen and printer scale can change a measurement.
03 / CONFIRMED PERSONALLY
The fit of your actual ring.
On a ring page, choose your requested US size or select “I need sizing help.” We confirm the actual ring, its current size and any possible adjustment before completing payment. A requested size does not reserve stock or guarantee resizing.
Any adjustment, fee or longer lead time is agreed before work begins. For a gift, tell us what you know about the wearer and a ring that already fits the intended finger.
Ask for personal sizing helpMeasurement reference: Tiffany & Co. size guide. Our available pieces and ordering terms are specific to Château Amaris.
