I ordered these 1 size larger based on the other reviews. I usually wear an 8 and ordered a 9. They fit perfectly. I have an average build and not a super skinny anything. These boots have a more narrow shaft than typical rain boots but are still wide enough to tuck your pant legs into them (narrow leg and straight leg). The zipper isn't as smooth as some but it's a kind of heavy-duty chunky material and I think that is why it zips roughly. I love these rain boots because they look like regular boots but are rubbery/waterproof and have lots of style. I ordered the black with red zipper. Too cute.