lmelanie - I wouldn't order a 40.5 (sorry). I have the multi-colored sandals and find they fit very TTS. I normally wear a size 8/38, but size up in some brands (Louboutin, Manolo). I took a 38 in these. I think they run quite wide (maybe b/c they were designed to wear with socks?). Hope this helps! Have you tried Barneys? They had them on sale recently.