There used to be standardization of bra sizes. Projection off the chest wall, 1" = A 2" = B 3" = C 4" = D, this went out the window a while ago. In most places women may be three different bra sizes depending on the type, model, fabric, etc. In your case it is much too early to tell. As far as going by cc, 500 may be large for a little female, but relatively small for a large female. Best to get fitted when your plastic surgeon says it is time.
I Had my Tissue Expanders Removed Yesterday and 500 Cc Silicone Implants Put in What is my Size?
Doctor Answers 3
Bra size after breast augmentation
You will need to get fitted for a new bra in order to know your bra size. A 500 cc implant may result in a large bra size in a 5'5'' woman who weighs 120 pounds and a much smaller bra size in a woman who is 5'10" who weighs 150 pounds. Plus, bra sizes can vary with different brands. The most important thing is that you like your breast size with the implants.
Implants do not come in cup sizes and for breast reconstruction, estimating how big a women will be for a given implant is difficult. It is too early to go bra shopping, but in the end you are the size that fits you.