Buttons

Ligne, the traditional unit for measuring buttons
Ligne MM Inches
14 9 3/8
16 10 3/8
18 11 7/16
22 14.2 9/16
23 14.88 5/8
24 15 5/8
30 19 3/4
32 20 13/16
35 22 14/16
36 23 15/16
40 25 1
45 29 1 1/8