Unlike the women's shoes, the men's shoes fit a little large. So follow these guidelines Guys: 1) Half sizes order down. For example, if you are a size 11.5, order the size 11. 2) Whole size order your size, but use the "Half-Sizer" insole to tighten the fit. 3) Same as with the ladies, a thicker pair of socks can take up a half size.