Ring Size Chart: US, UK, EU, and Diameter (mm)
Convert ring sizes between US, UK, EU, and inner diameter in millimeters, with instructions for measuring your ring size at home.
EU: 46.5
| US/Canada | UK/Australia | EU | Inner Diameter (mm) |
|---|---|---|---|
| 4 | H | 46.5 | 14.8 |
| 4.5 | I | 47.8 | 15.2 |
| 5 | J | 49 | 15.6 |
| 5.5 | K | 50.3 | 16 |
| 6 | L | 51.5 | 16.4 |
| 6.5 | M | 52.8 | 16.8 |
| 7 | N | 54 | 17.2 |
| 7.5 | O | 55.3 | 17.6 |
| 8 | P | 56.5 | 18.1 |
| 8.5 | Q | 57.8 | 18.5 |
| 9 | R | 59 | 18.9 |
| 9.5 | S | 60.3 | 19.3 |
| 10 | T | 61.5 | 19.7 |
| 11 | V | 64 | 20.5 |
| 12 | X | 66.5 | 21.4 |
How to Measure
Wrap a strip of paper or string around the base of your finger, mark where it overlaps, and measure the length in millimeters — this is your finger's circumference. Divide by π (3.1416) to get the inner diameter, then match it to the Diameter (mm) column. Alternatively, measure the inner diameter of a ring that already fits well using a ruler.
Notes
Ring sizes are most reliably compared via inner diameter or circumference in millimeters, since the US, UK, and EU systems use entirely different numbering conventions (numeric, alphabetic, and numeric-but-different respectively) with no simple offset between them. Finger size can also vary by time of day and temperature — measure when your hands are at normal temperature, not after exercise or in cold weather.
Frequently Asked Questions
Source: Compiled from common international jewelry sizing standards · see our methodology