I should have sized up 1 full size but they are still OK.  I went with 39 and it was a touch too small, Normally I wear a size 8 and thought an 8.5 would do.  That's my bad.  Besides, if I wear the top strap under my foot instead of on top, it works.  If you buy them, go up a full size.  I'm going to try the ballet flats next.  These are so easy to wear because it's simple to get them on.  Everything stretches.