One Size Fits Most. Fits best on size medium on up to size 1X. Model is 5 feet 6 inches tall and she has on 3 inch heels. Dress measures 54 inches long from the top of the shoulder to the bottom of the hemline. The dress will fall longer when it is worn off the shoulders. Model typically wears between size large and xlarge which is between size 12 and 16. Models bust measures 40 inches, waist 34 inches and hips 49 inches. The body of the dress has plenty of stretch. This fabric will stretch to fit. Please keep in mind that the dress is form fitted and is design to fit tight mermaid style. We feel it will fit up to size 18 or 20 comfortably. Fabric is cotton, silk and spandex blend. Great stretch. Wear on or off the shoulders. Side pockets