I have two boys aged 12 and 13. Thin, thin, tall. I usually buy 14-16 because they are big. My God. This shirt barely fit. The hands were up to the middle of the forearm. They were ultra fit. Where the arm meets the bodice, the seam is cut into the armpit. So bad. It was more like 10-12. I had to leave a package because I opened it (junk). Washed to donate to charity and he shrunk! I will take a picture of them wearing it and it is wrong compared to the size 14-16 on these shirts vvvvvvv. So…

I love these shirts! My boys wear them to dance class. They're long enough to fully cover the waist of the leggings, and the sleeves don't impede movement or ride up. They are very thin but comfortable, ideal for physical activity. After several washes they have become even softer and shrinking has not affected their fit. I think they are meant to be worn as tank tops and for that purpose I think they would be very nice without being bulky under a top layer. My boys are almost 4 and we are size