I wear a 2XL in most clothes, so that's what I ordered. The shirts are about an XL in the chest and waist, but the top straps are for a very tall person. On me they were so long that the front doesn't cover my nipples. The shirt fits fine in the sides and back.On the plus side, the colors are bright and strong, and do not fade in the wash. Sweat soaks through immediately and evaporates. The shirts do not shrink.