I got this pair form Crocs.com. I wear 7.5 most of the time, some times I can wear 8 if I wear thick socks. But this pair, I got size 8( cause they don't have half size), I feel like it's at least size 8.5 or 9. Even I wear thick socks, I still have lots of space left on length and width wises. But luckily, I just wear them as slippers around the house, and I like my slippers feel loose on my feet, so those large size shoes work out for me. But if you want true fit, like my usual size 7.5, I will go for size 7 for sure. Btw, they are so comfortable, great shoes to wear around the house.