What size bra am I?

[SunshineDeLaSoul]

'm currently wearing a 34c or 34b depending on the make.

I measure 34' under my breasts and 40" bending over.

Am I in the right size? The straps keep slipping off.

Try a 34E as a starting point

Agree with above poster , 34e/f depending on the style. Grab an armful In these sizes at a department store and try them on if you have time.

Use this - I was wearing the wrong size bra, used this, came out right. I went to Bravissimo after and got it properly checked so I know it's right.

booborbust.com/#info_tab

I was wearing a 34D and I'm a 32E

Thanks, the 34c cup is quite baggy, even with scooping so I'm a bit unsure what an E would look like. I will try though, and will let you know.

Try a half cup or balconette style.
Is the band around your chest snug? This is the part that should be doing the hard work.

Yes the band is the main bit. My D cups gaped but E cups don't, it does all kind of rearrange at different sizes. It also depends on the shape of your breasts, you won't fit the same in all styles. My boobs work best in a t-shirt style bra because they're quite round, but everyone is all different shapes