My son is 19 years old, he wears small clothes, he was just looking for long sleeve plaids and he loves it. I would suggest buying a t-shirt in your normal size. should fit well.
Gildan Performance Men's π Clothing and Shirts with Moisture-Wicking Polyester
44 Review
Van Heusen Traveler Stretch Men's Shirt
47 Review
π Nantersan Placket Raglan Tee - A Casual Must-Have
52 Review
Calvin Klein π Herringbone Sleeve Men's Dress Clothing
50 Review
Off White Men's Clothing: Amazon Essentials Lightweight Active Sweatshirt
42 Review
Carhartt Crewneck Sweatshirt Regular X Large
Cimic Black Athletic Short Sleeve T-shirts 520
Optimized Airflux Sleeve for PGA TOUR Standards
43 Review