Ring Size Comparison Table

USA U.K Diameter (mm) Circumference (mm)
6 M 16.40 52.00
7 O 17.30 54.50
8 Q 18.10 57.00
9 S 18.90 59.50
10 T 1/2 19.70 62.00
11 V 1/2 20.60 64.50
12 Y 21.40 67.50