My daughter is an average sized 7 year old so I ordered her a medium, size 8-10. It was extremely too small. It fit my four year old, and it was even a little tight on her. I returned it to the store without any problem. The material was nice and I liked that it came with all of the accessories, because a lot of times you have to purchase those separately, but it was just way too small. The sizing is definitely off.