These are women's sizes, even though this shoe is unisex.  If you're a man, use this conversion and consider ordering up .5 size.  I ordered a 10.5 for my son, who is a men's size 8.5.

Women to Men Conversion Chart
Women's (US); Men's (US)
5.5;  4
6;  4.5
6.5;  5
7;  5.5
7.5;  6
8;  6.5
8.5;  7
9;  7.5
9.5;  8
10;  8.5
10.5;  9
12;  10.5
13; 11.5
14;  12.5

(Sorry, it won't let me format this into columns)