This hat is huge. Seriously. HUGE. I bought the newborn - 6 month size for my newborn and knew it was too big when it arrived, but since it was my first child and I didn't have a good reference for head size through the months I thought she might need just a little time to grow and for it to fit. She's now 6 months old and the hat is still WAY too big! It may fit for next summer, but was a complete wash for the time I wanted to use it. I'd go with another brand for a baby under six months of age.