Fantastic hats to protect my kids from the harsh aussie sun. This summer has been a scorcher, and these have really come in handy. I purchased the L/youth for my 5 yr old, and the M/child for my 2 yr old. Both fit well with plenty of room to grow. The L size also fits my 2 year old when the strap at the back is tightened all the way, and I almost bought the L for her too, however I am glad I went with the M as she is sml for her age and the wider brim on the L looked a bit ungainly/uncomfortable for her. Only negative is that the strap under the chin and the clip on the side is a bit fiddly, and they certainly have trouble doing it up themselves. Not sure how long these clips will last with wear and tear over time. Still giving these 5 stars because they are great hats.