Bra Size

[kloofnek]

Can anyone tell me how I can get a bra with the correct back size.I know sizes vary according to makes these days .I have a 40d bra,the cup fits great but the back is a bit tight.Would a 42 c for example,have the same size cup and wider back?
Thanks

[kloofnek]

Oh gosh,did expect so many responses,Thank you and have a lovely evening

[woofgang]

kloofnek try BooborBust or go and find their facebook page. I promise you its life changing. https://booborbust.com

[woofgang]

sorry I have just read the previous answers which are what I thought until recently. Cup size DOES vary with band size. The old plus 4 or 5 system doesn't work.. I know I sound like a ranting old woman from Speakers Corner but its amazing how a properly fitting bra can change your life.