The size chart on these things could be better. I sifted through all the reviews to try to find recommendations for my size instead of relying on the size chart. I went with a size MEDIUM and wear a size 9.5-10 Women's shoe. Snug fit, but you have to remember that if you plan to wear them while wet, they need to be snug otherwise they will sag and fall off once saturated with water. I ordered a size up for my husband who wears a size 10-10.5 Men's shoe and they fit well. I hope this helps…

I am thoroughly impressed by the product. It fits just right,came when it was supposed to. I have an amazing autistic son. With sensory issues. He loves them so much. Wears often. Hes going on his first trip to Michigan,never been to beach. So thank u for a fabulous product and awesome quality.