These fit perfectly and are so comfortable, and if we ever get warm weather here in Central PA I know they'll be my go-to shoe for the summer.  I have Vionic in a sandle and a flexible ballet shoe (forget the style name, but their pewter) and they are both 10 and fit perfectly, but I was concerned about a more firm enclosed shoe.  They'll look cute with jeans or leggings, and I know I'll also be ordering another color of this shoe. I've had Plantar FAiciatis and have flat arches so there are just 4 brands I can wear: Vionic, Alegria, Klogs and Merril (some Merril need orthotics).  In all the other brands my size varies based on the style of the shoe, but evidently not Vionic.  Size 10 seems to fit whatever the style.  Good to know.