I wear an 8 1/2 ordered a 9. The foot was okay, but it is really small in the shaft and I wouldn't be able to wear anything other than a thin sport sock. The lining isn't very thick so I don't think that affected the fit much. I'm 5'7" 150 just to give you an idea. If your taller and or lighter they may be fine for you. I sent them back and ordered a size up, I'll update later.

Update: Exchange was quick and very easy. Sadly the 2nd pair was not any larger in the shaft. I guess it makes sense because of course bigger feet does not mean bigger calves. I returned the 2nd pair and already received the refund. Thank you for the great service.