This is the third RuffleButts swimsuit I have purchased. They are extremely cute. We love the long sleeves, so we don't have to use as much sunscreen. I bought one for each of my granddaughters. Then they needed swimsuits as their house, so those 2 disappeared. The size 4 fits the 35-pound, slender, 4-year old perfectly. A size 8 fits the 66-pound, tall, slender nearly 8-year old now, but there's not much growth room. Unfortunately, RuffleButts doesn't make a size 10, so I ordered another size 4 only.