I'm 60+, in relatively decent shape, 135 lbs, and size 6 is perfect. i went for the regular rather than petite sizing, which came well below my knees, and although i would usually have a sheath dress like this hemmed up to that slim part right at the bottom of the knee, the slim silhouette shape served to lengthen the profile as a longer dress, so i left it about 3" below the knee. the stretch allows it to hug the body, and with the right undergarments, it is super comfortable and attractive. go