Ladies, I have been to many festivals and lingerie shows, and one of the biggest problems we encounter when we get there, is that most people are a bit unsure about what bra size they really should be wearing.
Some posh shops will tell you to make the underband so tight, that you cannot breathe! I'm sometimes surprised how ladies dress size 22 are squeezed into a 38 bra, with red ridges and marks under their boobs. It's really up to you, but I personally feel more comfortable if I'm able to breathe, haha.
Here is a great guide :
Measure underband, as tight as you feel comfy with (not too loose!), and then measure the widest part of your boobs. In my experience, its way more accurate if you get a friend to do it. If I do it for myself, I am always wrong....not so easy to do on yourself.
If we use inches, then take the difference between underband and boob measurements.
USA BRA CUP
Test it, and let me know what you think? I am a perfect 38DD, so 5' difference. But do ask a friend to help!
Ask me if any questions firstname.lastname@example.org