I normally wear a size 8.5 US/39 Euro, and after reading the reviews decided on a size 9.  They fit perfectly, the straps are soft and do not chafe.  I did a side by side comparison of 2 other pairs of EVA wedge flip flops I have, both size 8.5, and they are the same in length, but narrower slightly in width.  For reference, they are the same size as my Coach "Jolene" wedge sandals, which say size 8.5 on the band.