Cute shoes.  Love the cushioned insole.  Wish like other reviews that it had a padded collar, my daughter has to wear socks with them because the collar is stiff and would cause a blister.  Definitely at least one size big.  If you go on the keen website and look at their size chart you can see, though.  My daughter has some size 11 sandals this shoe in 11 is a good 1/2 in longer than them.