My first order I went with an size 11 for my husband (per his request) because he wears a 10. Just run a half size small 5 out of 5 As long as you know what youre getting into, you should be fine. They fit well, and are both comfortable and stylish while providing proper foot support. It is very stiff but fits the windshield perfectly but does need to be folded and placed in the back seat when not in use. Plus, one of the Medium pairs came with only one shoe (a left one, if someone needs a single, blue, flip flop for their left foot). Great slippers, just as described! I got these for two major reasons: one, they are the right size for my ears, which are smaller than the usual bears, and two, uhhhh look at them. If you want a speaker that feels like a bang for your buck.