PEGAFFI · Education Guides · Design Your Ring
Ring Size Guide: How to Measure Your Ring Size at Home
2026-09-20 · 5 min read
A ring that spins is annoying; a ring that won't come off is a problem. The good news: you can find your size at home in five minutes with nothing more than a strip of paper or a ring you already own. PEGAFFI crafts rings in US sizes 8 through 25 — one of the widest ranges in fine jewelry — and every ring can be resized once for free within 60 days.
Method 1: The paper strip test (measure your finger)
- Cut a strip of paper about 10cm long and 1cm wide.
- Wrap it snugly — not tight — around the base of the finger you'll wear the ring on.
- Mark where the paper overlaps, then measure the length in millimeters. That is your finger's circumference.
- Match the circumference to the chart below to find your US size.
- Measure 3 times, at different times of day, and use the average.
Method 2: Measure a ring you already own
Take a ring that fits the intended finger well. Measure its inner diameter in millimeters — straight across the widest inside point, edge to edge, not including the metal itself. Match that inner diameter to the chart. This is the more accurate of the two methods, and the best way to size a surprise ring: borrow one they wear on the correct finger for a day.
US ring size conversion chart
| US Size | Inner Diameter (mm) | Circumference (mm) |
|---|---|---|
| 8 | 18.1 | 57.0 |
| 9 | 19.0 | 59.5 |
| 10 | 19.8 | 62.1 |
| 11 | 20.6 | 64.6 |
| 12 | 21.4 | 67.2 |
| 13 | 22.2 | 69.7 |
| 14 | 23.0 | 72.3 |
| 15 | 23.8 | 74.8 |
| 16 | 24.6 | 77.4 |
| 17 | 25.4 | 79.9 |
| 18 | 26.2 | 82.5 |
| 19 | 27.0 | 85.0 |
| 20 | 27.8 | 87.6 |
| 21 | 28.6 | 90.1 |
| 22 | 29.4 | 92.7 |
| 23 | 30.2 | 95.2 |
| 24 | 31.0 | 97.8 |
| 25 | 31.8 | 100.3 |
Five sizing mistakes to avoid
- Measuring cold fingers. Fingers shrink in cold and swell in heat — measure at room temperature, in the evening, when fingers are at their largest.
- Forgetting the knuckle. The ring must pass over your knuckle. If your knuckle is much wider than the base of your finger, size up half a size and consider sizing beads.
- Measuring once. Finger size fluctuates with salt, hydration and time of day. Three measurements, average them.
- Ignoring band width. Wider bands (over 4mm) fit tighter — go up half a size for wide bands.
- Guessing for a surprise. Borrowing an existing ring beats guessing every time. When in doubt between two sizes, size up — a slightly large ring is wearable; a small one is not.
What if it's wrong?
Gold rings resize easily — typically up or down one to two sizes without compromising the setting. Every PEGAFFI ring includes one free resize within 60 days, and our made-to-order model means we can also craft most styles in any size from 8 to 25 at no extra charge.
Still unsure? Contact us and we'll mail you a free reusable ring sizer — the same jeweler's tool in the photo above — before you order.