Indian Size	Diameter (mm)	Circumference (mm)	US Size
6	14.6	45.9	3.75
7	15.0	47.1	4
8	15.3	48.1	4.5
9	15.6	49.0	5
10	16.0	50.3	5.5
11	16.3	51.2	6
12	16.6	52.2	6.5
13	17.0	53.4	7
14	17.3	54.4	7.5
15	17.6	55.3	8
16	18.0	56.5	8.5
17	18.3	57.5	9
18	18.6	58.4	9.5
19	19.0	59.7	10
20	19.3	60.6	10.5