I can't speak for the smaller sizes, but starting with X-Large and going up I believe this is what has gotten confused:

X-Large is as it states in the main drop-down menu (i.e., Mens size 9.5-11 B-width/Women's size 11-12.5 B-width).

XX-Large (or 2X) is listed as Men's 12.5-14. In other words, the Men's sizes 11.5-12 are NOT LISTED ANYWHERE. My guess is that they really go like this:

XX-Large (2X) is Men's size 11.5-13 (or Women's size 13 and over if there is such a thing)

XXX-Large (3X) is Men's 13.5-15 (not 14-15.5 as listed).

This would also explain the reviews where some of the larger men's sizes were found to run small. I got the 2X size for my son (who wears men's size 11, since I would rather they run a bit large than too tight) and I got X-Large for myself (a women's size 11) for the same reason.

I hope this helps. The people at Toby's Tool Shed are very nice and I highly recommend the boot as well as the company that is selling them as very helpful and kind.

Later addition to this review: After wearing these more times I have discovered that black rubber comes off onto my right heel at times (very hard to wash off) and also onto the tops of whatever shoes I am wearing inside of these shoes. For this reason I recommend wearing only scruffed-up shoes inside these boots!