These ran slightly small for me - I am a solid 8 and I had to return for 8.5. I've only owned rounded JS heels in the past and the 8 still fits. Pretty great for 4in heel. I wore these for a conference and I felt pretty good for most of the day, esp since I got to sit down. I would say if you had to stand continuously I wouldn't wear for more than 3-4 hours.