That's all you really need to know.But for more details, the size charts in China are usually screwed, they don't really enforce any quality control (your brand name does it for you), and the material is pretty awkward feeling on the skin.
Gildan Performance Men's π Clothing and Shirts with Moisture-Wicking Polyester
44 Review
H2H Mens Casual Slim Fit Short Sleeve T-Shirts Cotton Blended Soft Lightweight V-Neck/Crew-Neck
46 Review
Men'S Long Sleeve Polo Shirt - Slim Fit, Stretchy, Breathable Collar
43 Review
Calvin Klein π Herringbone Sleeve Men's Dress Clothing
50 Review