Review on 👕 Boys' Royal Performance Tops, Tees & Shirts - Amazon Essentials 2 Pack by Mark Morrow

My 9 year old tall guy. I originally ordered a size 10 knowing I might have to exchange it. I did and bought a size 12 instead. Fits great. Covers the stomach when raising the arms and relaxes without tightening the chest area when lowering the arms. He really likes the Dri-Fit material. If your son is of average height, 10 is probably perfect for a 9-10 year old. If he were a husky I would go up a size if that makes sense. The exchange process was easy. There is a return label just in case.