Approximate size guide based on previous customer feedback:

Small:
28E, 28F, 30A, 30B, 30C, 30D, 32A, 32B, 32C

Medium:
32D, 32DD, 34A, 34B, 34C 

Large: 34D, 34DD, 36A, 36B, 36C

Xlarge: 36D, 36DD, 38A, 38B, 38C