38j fit true to size. Extremely comfortable. It provides a smooth lift and the band and bra material are comfortable even with all day wear. As there's no underwire or cups, this bra doesn't provide much separation, but it doesn't press them together into an awkward middle uniboob like most sport bras do. This is my favorite bra for comfort when I'm running errands or just hanging around the house. I wouldn't wear this as a sports bra or with a lower cut v neck shirt. Its comfortable in the arm pit area even with my breasts that extend to my sides a bit.