I got this for my daughter, she is 3 months old.  I got the size (newborn) because of reading other reviews on how this hat is big for the size.  This is so very true if i were to get the one size bigger she wouldn't have been able to wear it for a long time.  The hat fits great!! There is some room for her head to grow but works well for the cold Wisconsin days and nights.  The velcro on the chinstrap is great.  The rough side is facing out so it's not close to your child's skin and it goes under her chin and stays in one spot well.  She likes to move her head back and forth to see everything and the hat keeps up with her movements.