I've been looking for a bra intervention thread but can't seem to see a recent one.
With one thing and another my bra size has changed. My once nicely fitting bras aren't fitting so well now so I decided to measure myself with the help of some bra fitting guides on google. I wish that I hadn't bothered.
My measurements are 31 inches under the bust and 36 inches around the actual bust. I thought that measuring would be standardised but apparently not. I'm coming in at 32d, 34c and 36b depending on what guide I use. I'm currently wearing a 32d and my Debenhams bras are a little loose in the cup although look fine when I stand up straight 
I can appreciate that different shops will have different sizing (like all clothes). I suppose that I'm going to just try a few on and see what fits best. It's such a faff taking everything off.