I have not had any success buying bras based on taking measurements myself, so I just ordered my usual size 10E. The cups fit well, but the band was very tight. Rather than exchanging it, I bought a bra extender from a local department store, which worked perfectly! The bra extender is unlikely to be compostable, but I will be able to use it with other bras as well. I think that means I should order a 12DD next time.