Yes from armpit to armpit is 18 inches, and the length from the top of zipper to hem is 33 inches, I looked at the size and it is a 6P not a 1, I hope this help you
You ask for the measurements and when I made them I found the owner had given me the wrong size, I gave you the measurements and changed the size so you would not make a bid on a size that was not correct, I dont know what else to say except that I did not want you to get a dress that was not the right size. Lois