I am not a regular flip flop user but wanted something that was easy to slip on in the morning.  They are very comfortable. I normally wear a size 8 B or C and the medium were a good fit with a little wiggle room to spare. My only complaint is that the edges beyond the stitching extend out too much (especially along the front)  and I find myself walking funny to avoid catching them on the floor--it feels like wearing a shoe that is too large. By the time I realized this would be a significant issue, I had worn them too much to return them.  I am using them but this is a purchase I would not make again.