I am a size 7.5 and bought the 7.5 and it was big so I returned it for the 7 and they fit perfectly. I love these boots. I use them for walking my 3 dogs in the rain and mud in Houston. I need something sturdy that can help me resist the pulling of a 60 pound husky and these boots do the trick. If you sometimes go between two sizes, go for the smaller size. It runs a half size big.