"I found these shoes to run a little big. I am a 6 and i noticed there was a little bit of a gap but my foot was not slipping out of the shoe. The 5.5 was a little too snug though. I purchased some sole cushions to fill the shoe up and this did the trick. I love these shoes as they are comfy and great for work. The heel is not too high and they just look classy and are a great look."