I am a traditional size 8 US / 39 EURO. Sometimes I even where a 71/2 or 38 Euro. These sandals are labeled as being "US 8; Eur 40" on the inside tag of shoe, and yet I feel that they run small. My toe comes all the way to the end and my heel hits the back. This is yet another company that does not make half sizes, so I'm not sure if I will be keeping these. If they offered an 8 1/2 I would exchange them. The arch support is great, but overall I'm disappointed.