These are a full size smaller than regular Chaco sandals (Cloud and original). In regular Chaco sandals, I wear a 6. These were way too small on me, though. I compared them side by side to my regular Chacos (Z1), and the Zvolvs were about a quarter inch shorter than the Z1s.
In normal shoes, I wear a size 7. If I had purchased the 7s in these, they might have been fine.
Moral of the story: in purchasing these, DO NOT go off of your regular Chaco size. Instead go off of your normal shoe size in other brands.