Measuring bra size!

Al

New mom that doesn't want to take the time to go to the store and get measured for a new bra. I know I've seen ways to do it at home BUT they all say to wear your bra while measuring....the thing is all of my pre baby bras are way too small in the bust and the band and all of my maternity bras are way too big in the band and bust 🤦🏻‍♀️

Will I be able to get an accurate measurement wearing either a bra that is too small or too big?