I'm a 34C and I ordered a 34C and 32C.  The 34C I can wear on the last hook.  I gave it four starts for only one reason.  My only complaint is the band under my bust curls up and this drives me nuts.  Very supportive for running.  The 32C is a little tighter fit, but all my bras stretch out, so I wear it on the first hook and will tighten after it stretches.  Love the adjustable straps, this is the best feature about the bra.