I love these boots.  I normally wear an 8.5 (or a 9 if it's a style with a narrower toe box), but based on other reviews I decided to go with an 8.  The 8 absolutely fits like a 9 so I will have to wear thicker socks with these if I plan on wearing them for any long length of time.  I'm concerned about blisters from them slipping around due to all the extra room.  Otherwise they're adorable and seem well made, and are comfortable and substantial, unlike other cheaper rain boots that are thin and flimsy.  The adjustable gusset at the top is perfect for ladies with larger calves, but if you have average or smaller size calves you will probably not get a snug fit at the top of the boot.  The smallest adjustment is the best fit for my calves (14.5-15" circumference)  but it looks funny when they are adjusted on the smallest hole - the gusset flares out at the top and bottom and just looks weird.  I put mine on the second smallest setting and while it's a little looser than I'd like, this gives the gusset enough room to lie flat.