I am normally a medium, but because I was worried about the hips measurements, I ordered a large.  It says that a large should fit a 40 bust, I am a 36" and it barely fits. The same thing in the waist. I'm going to add a few snaps along the back because the velcro is not going to work.  The apron is the opposite, it is huge.  I cut the straps on it to shorten them and moved them over for a better fit.  Now I wasn't expecting a fitted costume, but there are definitely some issues with sizing.  How does someone who is a size 8-10 (6 in some dresses) need to order an XL to have the dress fit.  I do like the outfit overall.