Our Relaxed Fit Tee (Bella + Canvas style 3001) is a unisex style that runs a touch small for men, and about a half a size large for women. It's a relaxed fit and is soft and cozy. Occasionally we substitute American Apparel 2001W, which is sized the same way. (Sometimes it can be hard to get all the shirts we need in a given size/color combo, so we like to have a comparable backup!)
Our Ladies Snug Fit Tee (Bella + Canvas Style 6004) is a fitted, body-hugging style, and it runs small. We generally recommend ordering a size up for a fitted look, or two sizes up if you want a little more room. However, this is a fitted style, designed to be tight. If you prefer a relaxed fit we strongly recommend the relaxed fit tee.