Button size conversion

According to the button diameter size, that we now often say 14L, 16L, 18L, 20 L, 24L，26L, 28L, 32L, 36L……60 L and so on! Its conversion formula is: diameter = model * 0.635 (mm). If we do not know the exact button size, we can use calipers to measure out its diameter (mm) and then divided by 0.635.