I bought these in size 4 for my grandson who currently wears a 3T. The shirt is a little bit baggy and the shorts are a little bit long, but the waist elastic is a little bit snug. So, I think as far as size goes, it’s accurate for a child wearing 4, but might be even more snug in the waist. The fabric is very nice. Medium weight stretchy tshirt fabric for the shirt, cotton for the pants. Made very well, good hems and seams. The graphic is cute and well defined, and has been applied very well. They are his favorite and every night he insists he has to wear Grandma's PJs, as he calls them.