Are 450-485 cc implants too big? I’m 5’5 and 148 lbs. (Photo)

Thank you for the question and picture.
 Based on your photograph, I think that you are starting at a good place and should have a very nice outcome with breast augmentation surgery. My best advice: more communication.
It is definitely worth spending more time (prior to the date of surgery) with your plastic surgeon to discuss further.  As you know, it will be important for many reasons, that you feel comfortable that you and your plastic surgeon are on the "same page" prior to proceeding. One question that might be helpful to patients in your situation: would you be more disappointed if you are slightly too large or slightly too small?
Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures, direct examination/communication in front of a full-length mirror, in bra sizers, and computer imaging) as well as careful measurements (dimensional planning) will be critical.
Generally speaking, the best online advice I can give to ladies who are considering breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully. Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. For example, 
I have found that the use of words such as “natural or fake look” or "C or D cup” etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup size may also be inaccurate. Again, the use of computer imaging has been very helpful during the communication process, in our practice.
3. Once you feel you have communicated your goals clearly, allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals. Again, in my practice, this decision is usually made during surgery, after the use of temporary intraoperative sizers.
I hope this helps. Best wishes for an outcome that you will be very pleased with. 

Based
on your photo, you should achieve a very nice cosmetic result with a breast
augmentation.  The
best cosmetic result in any particular breast augmentation patient depends on a
variety of factors, including: your individual anatomy, desired outcome, realistic
expectations, a thorough discussion with the plastic surgeon about the options,
and an understanding of the pros and cons of any particular implant choice.
Proper sizing is not just about the number of cc’s. The thickness of your
tissue, breast dimensions which include the width, height, and projection, as
well as chest wall width all need to be considered when choosing an implant.
Trying on implant “sizers” of various shapes and volumes while wearing a tight
t-shirt, bra, or bathing suit at a preoperative visit will help you and your
surgeon choose the optimal implant.
Keep in mind that following
the advice from a surgeon on this or any other website who proposes to tell you
what to do based on a photo without examining you, physically feeling the tissue, assessing your
desired outcome, taking a full medical history, and discussing the pros and
cons of each operative procedure would not be in your best interest. I would
suggest you find a plastic surgeon certified by the American Board of Plastic
Surgery and ideally a member of the American Society for Aesthetic Plastic
Surgery (ASAPS) that you trust and are comfortable with. You should discuss your
concerns with that surgeon in person.
Robert Singer, MD FACS
La
Jolla, California

Hello and thank you for your question. You are a great candidate
for a breast augmentation.  In order to help determine if 450-485cc is the right size for you, it would also be helpful to know your individual breast measurements.  The size, profile, and shape of the
implant is based on your desired breast size/shape, your chest wall
measurements, and soft tissue quality.  This decision should
be based on a detailed discussion with equal input from both you
and your surgeon.  This entire surgery
can be performed with a small incision technique.  Make sure you
specifically look at before and after pictures of real patients who have
had this surgery performed by your surgeon and evaluate their results.   The most important aspect is to find a
surgeon you are comfortable with. I recommend that you seek consultation with a
qualified board-certified plastic surgeon who can evaluate you in person.
Best wishes and good luck.
Richard G. Reish, M.D. FACS
Harvard-trained plastic surgeon