If I am getting 300 cc, will my implants actually be filled to 320 or 330 cc since I am getting saline?

Some surgeon and over inflate their saline implants to reduce rippling.  I fill them exactly to the number on the implant itself.  Over inflating implants just slightly as recommended in your case should work out fine.

It is very difficult to determine the best lift you will need (recommended based on your photos) or the exact size and shape implant you will require to best match your ideal breast image without an examination by a board certified plastic surgeon. Not just any board certified plastic surgeon, but one with many years of frequently performing breast augmentation surgery including different approaches, techniques and implant choices. This is because several measurements not to mention your breast characteristics are needed to determine the optimal implant size to obtain your goals. Without knowing these dimensions it would be difficult to make this determination. For example, the existing base width of your breast will determine, in many cases, the maximal volume per implant profile that you can accommodate. To illustrate; a 100 cc difference may make a significant difference with a narrow base width breast, but much less of a difference if you have a wide chest wall and wide breast “foot print”. Therefore, just because your friend may have a great result with let’s say a 300 cc implant to make her go from a “A” cup to a “C” cup size does not mean that you will have the same result with the same size implant. The same process goes for just filling in the upper part of your breast without becoming much larger. Further simply placing implants in a bra to determine the size best for you is not always accurate as the bra often distorts the size, is dependent on the pressure the bra places plus the implant is outside your breast and not under it among other variables. Computer software morphing programs that automatically determine the best implant size can be helpful in some but not all cases (e.g. doesn’t work well in my experience with existing implants, sagging or asymmetric breasts). Using “want to be” photos however are useful if simply provided to the surgeon as I will further explain in the link below including silicone vs saline implants

In my practice, the 300 cc you described would be the final total volume. It's best to clarify with your surgeon whether the number he or she said is the starting or final volume. For more information on this and similar topics, I recommend a plastic surgery Q&A book like "The Scoop On Breasts: A Plastic Surgeon Busts the Myths."

that you have discussed with your surgeon.  The implants do have a range of fill volumes and you should discuss what you want that will provide you the look you want and eveness if you have asymmetric volumes.

In general there is a range attached to each implant . It could be 300-330, 300-350, or something similar depending on the company. In my practice I fill closer to the higher number as I believe an underinflated implant has a higher chance of rupture. But presently I use silicone almost exclusively. Review this with your surgeon.  The 20 or 30 ccs will not appreciably change the size. 

Most surgeons are trained to avoid under filling or minimally filling saline implant due to the greater risk of rippling and possible future leakage.  In my practice the rare to use saline implants these days I would fill 300 mL implant to anywhere between 315 and 330 mL.  Filling above the upper number is acceptable though less ideal but should not be done to great excess.  Best wishes,Jon A Perlman M.D., FACSDiplomate, American Board of Plastic SurgeryMember, American Society for Aesthetic Plastic Surgery (ASAPS)ABC-TV Extreme Makeover SurgeonBeverly Hills, California

Dear Ms. Elixirs 5467,Thank you for your question. Without knowing the exact manufacture, size and style it would be impossible to answer your question.Please contact your chosen Plastic Surgeon and he can easily answer your question.I trust you have a chosen a Bd. Cert. Plastic Surgeon who ideally is a member of the Am. Soc. for Aesthestic Plastic Surgery.My best,Dr. Hardesty, MD, FACS