I tried on a million dresses and this was the "one." I bought it and didn't have it altered. I kind of think it would fit someone who is regularly a 6 or up to an 8. Obviously the corset is adjustable, and the skirt can be taken in or out at the waist.
Size 8 corset Size 10 skirt
Watter's size chart: 38" 30" 40.5"