Definitely a size smaller (I had), my husband fits a large t-shirt (usually Gildan) and I bought him a medium size and it fits almost perfectly. maybe even a bit big.
Ashers Apparel Schrute Breakfast T Shirt Men's Clothing for T-Shirts & Tanks
34 Review
Ultimate Comfort: Discover the Comfort Colors Sleeve 6014 - X Large Men's Clothing, T-Shirts & Tanks
40 Review
Carhartt Workwear XXXXX-Large Men's T-Shirt β Original Clothing for T-Shirts & Tanks
34 Review
AM Fitted T Shirt 3 Pack for Men's Clothing - T-Shirts & Tanks
46 Review
Men'S Long Sleeve Polo Shirt - Slim Fit, Stretchy, Breathable Collar
43 Review
INFLATION Bamboo Shirts Sleeve Elastic Men's Clothing in Shirts
45 Review
Calvin Klein π Herringbone Sleeve Men's Dress Clothing
50 Review
Gildan Performance Men's π Clothing and Shirts with Moisture-Wicking Polyester
44 Review