My tall and thin 12yo typically wears 12 in shirts and pants. We ordered the size 14 in hopes to give him extra loose-fit room, but it was a snug fit and after the first cold wash with air drying, the length shrunk a bit as well. I bought this for his first Luau on the Hawiian islands vacation and it barely fit when he went to wear it. He would not choose to wear this shirt again due to the too small fitting but the print and color is really nice.