1
Measure a Ring You Own
Place an existing ring that fits well over the circles below until you find the closest match. Measure the inner diameter in millimeters.
2
Measure Your Finger
Wrap a strip of paper or string snugly around the base of your finger, mark where it meets, and measure the length in millimeters.
3
Convert & Confirm
Match your measurement to the chart below. When in doubt between two sizes, choose the larger one — and remember knuckles!
Ring Diameter (mm) → US Size
The chart below matches the inner diameter of the ring to its US size.
17.3 mm
US 7
US 7
| US Size | Inner Diameter | Inner Circumference | UK / AU | JP / KR | EU |
|---|---|---|---|---|---|
| 4 | 14.8 mm | 46.5 mm | H | 8 | 46.7 |
| 5 | 15.6 mm | 49.0 mm | J | 10 | 49.3 |
| 6 | 16.4 mm | 51.5 mm | L | 12 | 51.9 |
| 7 | 17.3 mm | 54.4 mm | N | 14 | 54.5 |
| 8 | 18.1 mm | 56.9 mm | P | 16 | 57.1 |
| 9 | 18.9 mm | 59.5 mm | R | 18 | 59.8 |
| 10 | 19.8 mm | 62.2 mm | T | 20 | 62.4 |
| 11 | 20.6 mm | 64.8 mm | V | 22 | 65.0 |
| 12 | 21.5 mm | 67.5 mm | X | 24 | 67.7 |