I have other pairs of Kenetrek boots that run true to size, however the Grizzly runs small, quite small in my opinion. I wear a 12 in everything. I could barely get my feet in these with a plain cotton sock. Worst part is shipping them back is, or was for me and I shopped 3 sources to get these returned. I do like the look and function of the boot as a colder weather, lighter pac boot. Guidefitter and Kenetrek are great to work with, it's just the sizing description should instruct the buyer to order a size up. I just ordered size 13 and will update the review when I receive them.