Ring Size Guide
A considered fit
Find your U.S. ring size with confidence
The most reliable starting point is a professional measurement on the exact finger and hand where you plan to wear the ring. Our numeric ring-size options use the U.S. ring sizing scale; if a particular style shows Small/Medium/Large options, please contact us with your jeweler’s measurement before ordering rather than guessing at a conversion.
01 / The most dependable method
Ask a jeweler to measure you
Ask for a finger-gauge measurement in a U.S. size for the specific finger and hand. The ring should pass over the knuckle with gentle resistance, then sit comfortably without slipping or feeling tight.
02 / If you already own a ring
Measure the ring that fits
Bring a well-fitting ring worn on the same finger to a jeweler and ask them to read it on a ring mandrel. At home, a measured inside diameter can be a useful cross-check only if the band is perfectly round; string and paper-strip methods can stretch, shift, and miss the knuckle fit.
Reference chart
U.S. sizes and inner measurements
Use this as a reference, not a substitute for a jeweler’s gauge. Values are approximate; choose your product size using the U.S. option shown on the listing. Some styles offer quarter sizes or sizes above this chart—ask your jeweler for the exact U.S. size and contact us if you would like us to confirm the selection.
| U.S. size | Inside diameter | Inside circumference |
|---|---|---|
| 3 | 14.1 mm | 44.3 mm |
| 3.5 | 14.5 mm | 45.6 mm |
| 4 | 14.9 mm | 46.8 mm |
| 4.5 | 15.3 mm | 48.1 mm |
| 5 | 15.7 mm | 49.3 mm |
| 5.5 | 16.1 mm | 50.6 mm |
| 6 | 16.5 mm | 51.8 mm |
| 6.5 | 16.9 mm | 53.1 mm |
| 7 | 17.3 mm | 54.3 mm |
| 7.5 | 17.7 mm | 55.6 mm |
| 8 | 18.1 mm | 56.9 mm |
| 8.5 | 18.5 mm | 58.1 mm |
| 9 | 19.0 mm | 59.7 mm |
| 9.5 | 19.4 mm | 60.9 mm |
| 10 | 19.8 mm | 62.2 mm |
| 10.5 | 20.2 mm | 63.5 mm |
| 11 | 20.6 mm | 64.7 mm |
| 11.5 | 21.0 mm | 66.0 mm |
| 12 | 21.4 mm | 67.2 mm |
| 12.5 | 21.8 mm | 68.5 mm |
| 13 | 22.2 mm | 69.7 mm |
| 13.5 | 22.6 mm | 71.0 mm |
A few details that change the fit
- Measure the exact finger and hand; left and right hands may differ.
- Finger size changes with temperature and time of day. Measure when your hands are at a comfortable, normal temperature, and avoid sizing immediately after cold exposure or strenuous activity.
- Every Seneca ring is made to order, and our team accounts for its design and band profile when preparing your selected U.S. size. You do not need to order a larger size solely because the band is wide.
- If you fall between sizes, ask the jeweler to compare both sizes on your finger rather than guessing from a conversion chart.
For additional professional guidance, see the Gemological Institute of America’s ring-sizing guidance. If you are unsure which U.S. size to choose, contact us before ordering.