I took the risk of buying a size 3 because that was the only size left and it was very cheap $ .Even though my daughter wears a size 6. I have these for myself and i had to size down. They fit her perfectly because they are very long and stretchy. I’m glad I took the chance they are good quality. For reference Shes 3 years old 48lbs 3’3. She’s kind of thick and still fit in a size 3.