Metal that lasts
How to Find Your Ring Size at Home (Accurately)
Paper strips lie. A ring you already own, string plus a chart, and measuring at night will get you within a quarter size.
Updated 26 Aug 2026 · 6 min read · how to find ring size at home
The method that actually works
A ring that already fits is a gauge. Place it on a ruler and read the inside diameter. 16.5 mm is a US 6. 18.1 mm is a US 8. Write both US and UK letters down; UK shops use L, N, P. Charts disagree by a quarter size at the edges — if you are between sizes, the larger one comes off more easily and can be sized down.
String is plan B. It must not stretch. Wrap the knuckle, not the base, because the ring has to pass the knuckle. This is the same “measure the hard part” logic as measuring a body for clothes.
| Inside diameter | US | UK |
|---|---|---|
| 15.7 mm | 5 | J½ |
| 16.5 mm | 6 | L½ |
| 17.3 mm | 7 | N½ |
| 18.1 mm | 8 | P½ |
| 18.9 mm | 9 | R½ |
| 19.8 mm | 10 | T½ |
Fingers change. Bands change them more.
Morning fingers are smaller. Heat, salt, flights, and luteal-phase swelling add a quarter to a half size. A 6 mm signet needs more room than a 2 mm band. If you work with your hands, size to the end of a workday.
When not to guess
Solid 18k and eternity bands are poor candidates for “I’ll resize it.” Buy the plastic sizer, or walk into any jeweler with the finger. For a cheap filled fashion ring in the everyday stack, a quarter-size miss is annoying, not tragic.
Questions, answered
- Are the cheap Amazon sizers accurate?
- The plastic ring-loop sets are. The paper printable PDFs are not, because home printers scale.
- Do men and women use different charts?
- No. The millimetre is the millimetre. Averages differ; the chart does not.
- My knuckle is two sizes bigger than the base.
- Size for the knuckle and have a jeweler add sizing beads or a spring insert so it does not spin.
