This is TOO BIG for a small. I am gonna have to take the sides in. I am a 30DD in bra’s for reference. This is more like a Medium/large with space under the rib area, making it prone to lifting up/moving around. I usually get sports bras in medium and they fit more snug than this bra does, so this is unusual. I would size 1 size down if you get this bra. Love the fabric, it has a nice thickness, and is made well, but be aware, it runs large.