Ring Size Chart
Find and convert ring sizes across US, UK, EU, and Japanese systems. All sizes include diameter and circumference in millimeters.
International Ring Size Conversion Table
Search or scroll to find your ring size. All measurements follow ISO 8653 standards.
| US | UK | EU | JP | Diameter (mm) | Circumference (mm) |
|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 14.0 | 44.0 |
| 3.5 | G | 45 | 5 | 14.4 | 45.2 |
| 4 | H | 46 | 7 | 14.8 | 46.5 |
| 4.5 | I | 48 | 8 | 15.2 | 47.8 |
| 5 | J | 49 | 9 | 15.7 | 49.3 |
| 5.5 | K | 50 | 10 | 16.0 | 50.3 |
| 6 | L | 51 | 12 | 16.5 | 51.8 |
| 6.5 | M | 52 | 13 | 16.9 | 53.1 |
| 7 | N | 54 | 14 | 17.3 | 54.4 |
| 7.5 | O | 55 | 15 | 17.7 | 55.7 |
| 8 | P | 57 | 16 | 18.1 | 57.0 |
| 8.5 | Q | 58 | 17 | 18.5 | 58.3 |
| 9 | R | 59 | 19 | 19.0 | 59.5 |
| 9.5 | S | 60 | 20 | 19.4 | 60.8 |
| 10 | T | 62 | 21 | 19.8 | 62.1 |
| 10.5 | U | 63 | 22 | 20.2 | 63.4 |
| 11 | V | 64 | 23 | 20.6 | 64.6 |
| 11.5 | W | 65 | 24 | 21.0 | 65.9 |
| 12 | X | 66 | 25 | 21.4 | 67.2 |
| 12.5 | Y | 68 | 26 | 21.8 | 68.5 |
| 13 | Z | 69 | 27 | 22.2 | 69.7 |
| 13.5 | Z+½ | 70 | 28 | 22.6 | 71.0 |
| 14 | Z+1 | 71 | 29 | 23.0 | 72.3 |
| 14.5 | Z+1½ | 73 | 30 | 23.4 | 73.6 |
| 15 | Z+2 | 74 | 31 | 23.8 | 74.8 |
Ring Sizing Systems Explained
US & Canada
Numerical scale from 3 to 15 with half sizes. The most widely used system in North America. Each whole size increment equals approximately 0.8 mm in diameter.
UK & Australia
Alphabetical scale from A to Z, then Z+1, Z+2, etc. Used in the United Kingdom, Australia, New Zealand, Ireland, and South Africa.
European (EU)
Based on the inner circumference in millimeters, following the ISO 8653 standard. Used across most of continental Europe. Simple and precise.
Japanese (JP)
Numerical system used in Japan. Sizes typically range from 1 to 30+. Based on the inner circumference, similar to the European system but with different numbering.
Ring Sizing Tips
Measure at the end of the day when your fingers are at their largest. Fingers swell throughout the day and in warm weather.
Wide bands need a larger size. Rings wider than 6mm typically require going up half a size for comfort.
Consider your knuckle. If your knuckle is much larger than the base of your finger, size for the knuckle and consider a comfort-fit band.
When between sizes, go up. A slightly loose ring is more comfortable than one that's too tight.
Measure multiple times. Take 3-4 measurements on different days to account for normal size fluctuations.