Ring Size

Internal
Diameter (mm)
Circumference
(mm)
US & Canada
Size
Japan
Size
14.9
46.8
4
9
15.7
49.3
5
12
16.5
51.9
6
14
17.3
54.4
7
16
18.1
57.0
8
18
19.0
59.5
9
20
19.8
62.1
10
22