I have size 7.5 (Nike tennis shoes, I usually wear size 8) for reference. I followed other reviews and went down to 7 and they couldn't be more perfect! Let the flip flops speak for themselves, check out my photos π I love that the flip flops are made in one piece and not a separate tape on the foot that always finds a way to come apart at some point fall. Blue is EVERYTHING! It's also worth noting that I received my slides before the expected delivery date.