//US Ring Standard Sizes 3-16 with half values in mm. Keep spacing if edited!
3    = 14.07
3.5  = 14.48
4    = 14.88
4.5  = 15.29
5    = 15.70
5.5  = 16.10
6    = 16.51
6.5  = 16.92
7    = 17.32
7.5  = 17.73
8    = 18.14
8.5  = 18.54
9    = 18.95
9.5  = 19.35
10   = 19.76
10.5 = 20.17
11   = 20.57
11.5 = 20.98
12   = 21.39
12.5 = 21.79
13   = 22.20
13.5 = 22.61
14   = 23.01
14.5 = 23.42
15   = 23.83
15.5 = 24.23
16   = 24.64