My newborn is 3 weeks tomorrow and I picked up a set of these hats a few days ago at our local Target.  The size does say 0-6 months and I figured that since my baby is not even 3 weeks these would be perfect.  Wow, I was so wrong, these hats are tiny.  They are just way too small even for my newborn baby!  My son weighs 8lbs and is in the 51% for weight and 25% for height and his head is smaller then the average size newborns head of 14", his is 13".  Anyhow, these hats are just TINY and do run really really small.  I would of returned them to our local store but I cut and threw out all the tags.  A lesson learned, try on the items before discarding anything!  So, buyer beware!  If you buy these know they are tiny!