They fit maybe 1 1/2 sizes larger than numbered. I'm size 11 and ordered that. They're really loose. Good with 3 pairs of socks. My friend, size 13, finds them a bit tight. I don't ever wak far in them and it's important they go on/come off east, so they're ideal. If I were walking in them I'd need a ten. Well made, light and dry.
