I purchased the size large and this swim hat fits my average size 2½ year old perfectly. The brim of the hat is just big enough to protect her face nicely. The only improvement I suggest is changing the closure to a couple of snaps or soft velcro (instead of the laces to tie).
Hey Karen! I am so happy to hear that this hat fits your little one perfectly! Glad that the wide brim on this hat is the perfect size to protect your little one from the sun :)