Find My Ring Size
Not sure of your size?
Pick the closest. Every order comes with one free 30-day size exchange — we cover the shipping both ways. So you can commit without locking in a number.
The fastest way: measure a ring you already own
Grab a ring that fits the finger you're sizing for. With a millimeter ruler, measure the inner diameter — straight across the inside of the band. Match the millimeters to the Inner Diameter (mm) column below.
This is the most accurate method and takes 30 seconds. No supplies beyond a ruler.
Method 2 — Measure your finger with string
Wrap a length of string or ribbon around your finger. Make sure it crosses over the knuckle so the ring will slide on and off easily.
Mark where the string meets, lay it flat, and measure the length in millimeters. Match the millimeters to the Circumference (mm) column below.
Method 3 — Print our ring sizer
Download the printable ring sizer →
Print it actual-size (100% scale, no "fit to page"), cut out the sizer strip, and wrap it around your finger. Follow the instructions on the sheet.
Size conversion chart
| US Size | Inner Diameter (mm) | Circumference (mm) |
|---|---|---|
| 5 | 15.7 | 49.3 |
| 5.5 | 16.1 | 50.6 |
| 6 | 16.5 | 51.9 |
| 6.5 | 16.9 | 53.1 |
| 7 | 17.3 | 54.4 |
| 7.5 | 17.7 | 55.7 |
| 8 | 18.2 | 57.0 |
| 8.5 | 18.5 | 58.3 |
| 9 | 19.0 | 59.5 |
| 9.5 | 19.4 | 60.8 |
| 10 | 19.8 | 62.1 |
| 10.5 | 20.2 | 63.4 |
| 11 | 20.6 | 64.6 |
| 11.5 | 21.0 | 65.9 |
| 12 | 21.4 | 67.2 |
| 12.5 | 21.8 | 68.5 |
| 13 | 22.2 | 69.7 |
| 13.5 | 22.6 | 71.0 |
| 14 | 23.0 | 72.3 |
| 14.5 | 23.4 | 73.6 |
| 15 | 23.8 | 74.8 |
| 15.5 | 24.2 | 76.1 |
| 16 | 24.6 | 77.4 |
A few measuring tips
- Fingers swell in warmth and shrink in cold. Measure at the end of the day, when warm for the most accurate result.
- The string or sizer should fit snugly but not tight — a well-fitting ring slides over the knuckle with light pressure.
- Avoid measuring when your hands are cold or wet.
- Between sizes? Go up. A slightly loose ring is wearable; a tight ring isn't. And the free exchange has you covered either way.
Still unsure?
Email help@foundrycut.com with your situation — we reply within one business day and can usually pin down the right size from a couple of questions.