I ordered the Medium 8-10, but its a little big. This is my usual size, but I felt as if it wouldve been too small if I ordered a smaller size. I am 53, 126lbs, 37 chest and petite.. Ive ordered similar swimsuits on Amazon and they fit true to size. Im surprised this one runs big...It does look cute, though. But the built in bra part is for busty gals... If you have a smaller chest it will swallow you up and look really weird..