Size Guide
Step 1: Find a ring that fits the finger you want to measure.
Step 2: Measure the inner diameter of that ring in millimeters (mm).
Step 3: Use the chart below to find your Cosmo ring size.
| Inner Diameter (mm) | Cosmo Size (UK) | Cosmo Size (US) | Cosmo Size (EU) |
|---|---|---|---|
| 15.7 | F | 5 | 49 |
| 16.1 | G | 5.25 | 50.5 |
| 16.5 | H | 5.75 | 52 |
| 16.9 | I | 6.25 | 53.5 |
| 17.3 | J | 6.5 | 55 |
| 17.7 | K | 7 | 56 |
| 18.1 | L | 7.5 | 57 |
| 18.5 | M | 8 | 58.5 |
| 18.9 | N | 8.5 | 60 |
| 19.3 | O | 9 | 61 |
| 19.7 | P | 9.5 | 62.5 |
| 20.1 | Q | 10 | 64 |
| 20.5 | R | 10.5 | 65 |
Tips for Accurate Sizing
- Measure your ring or finger at the end of the day, when fingers are slightly larger.
- If you're between sizes, we recommend choosing the larger size for comfort.
- If you don't have a ring to measure, wrap a strip of paper or string around your finger, mark it, and measure the length in mm to find your ring size.