I have question on how exactly to measure my armpit to armpit size. Naturally with clothes this is self explanatory but on my body I have a few questions. Do I simply measure straight across my chest to where my armpit starts or does the tape measure actually needs to go underneath my arms some into the armpit area? Also it is safe to safe that with a small/high armhole jacket, chest size can be found by doubling the armpit size? Basically I messed up my sizing on a black scissors jacket by taking wrong measurements. I plan on selling the jacket and ordering another one.