I got two of these, for two little girls 3 and 5 years old.  The hats are true to size.  If your kid is 5 years old, then you should get him (her) size 5 and Up.  Great sun protection, perfect when windy, durable, float!  What else can you ask for?  A bit funny, look like something Vietnamese people wear (at least in the movies).  Great buy!