What Breast Implant Size is Too Wide or Too Narrow? 5'6, 125lbs, 34B wanting a full C Cup

I am 5'6, 125lbs, 34B wanting to be a full C Cup after a breast augmentation, and I have a 12 cm. breast diameter. The only high profile implants that has a 12.0 cm. breast diameter is a 425cc. I feel that this implant size is too big. Can I go with a 375cc which fits a breast diameter of 11.7 cm. or can I go with a 400cc that fits a breast diameter of 11.9? My platic surgeon's nurse said the 375 or 400 would be too narrow and that I should go with a 425-475cc, but I really want a 375cc-400cc. What size cc should I go with? What size is too narrow or too wide?

Doctor Answers 17

Proper sizing of implants in primary breast augmentation

Fitting a breast implant to you rather than fitting you to a breast implant is kind of like fitting your foot to a shoe. The dimensions of your foot have to fit the shoe if it's going to fit and look right. If you choose the shoe size first and then try to make it work you may have a problem.

Implants are pillow volume but they fit properly if the base width fits within the internal width of the breast. The vertical height is the same in round implants and will generally automatically fit if the pocket for the implant is handled properly. It's the forward projection that you can choose and the tissues will accommodate within implants currently available from Allergan and Mentor that are scaled for their width.

If your breast width is 12 cm then, allowing for tissue thickness, the width of the implant should be around 11.3 cm. In a medium profile saline implant of Allergan or Mentor this would be about 250 cc's and will not only fit and look good but increase your breast size by about 1 and 1/2 cup sizes relative to what you started with and to your chest circumference which doesn't change.

Mentor does not have a high profile saline implant scaled to the same width as in the medium profiles so your next choice up is the Mentor Moderate Plus which falls between a medium and a high profile. This would be a volume of about 300 cc's and would make you look more than a cup and 1/2 bigger but less than two cup sizes bigger.

The Allergan (Natrelle) high profile saline implant that fits would be a 320 or 350 cc base volume implant and would make you look about two cup sizes larger.

I recommend the patient choose whether they want a saline or gel-filled implant and whether they want a low, medium, moderate plus (saline), or high profile (the names are different in gel-filled smooth, round implants) which will increase their apparent breast size by a cup to two cup sizes. The volume of the implant is determined by the width of the breast and the patient's choice of profile. Size increase cannot be measured exactly and breasts that are unusually wide or narrow will be exceptions.

Boulder Plastic Surgeon
4.0 out of 5 stars 1 review

Choosing the right breast implant size

I'm glad to hear that your surgeon is using your chest wall measurements (base width) to consider a range of implants just right for you. Volume alone is not the best way to predict your final post augmentation size. I consider two factors when selecting implants for my patients: 1.Dimensional planning
2.Gel Implant Sizing system Dimensional planning – The measurements of your chest wall are taken. Also, the breast dimensions including the height, width, and current dimensions of each breast form the basis of dimensional planning. Based on these measurements, the implant size is recommended. This will give you a unique breast implant that is suited for your body frame. Even your fitness levels and other relevant criteria are taken into consideration. It is you who will decide what you are comfortable with. Gel Implant Sizing system – During the preliminary breast implant consultation, you will be provided with an option to “try on” a variety of implant shapes and sizes. You can also visualize the possible outcomes of your surgery which helps you to get that perfect size to give you the shape that you longed for. This way your preferences are known and you can then pick a range of implants that will “fit” just right to give a soft natural fuller look. In your case, there is not much difference between a 375cc and 400 cc High profile implant. If you look at the dimensions of each of those implants, they are mere millimeters off. I would try sizers to help you make your decision.

Choosing the implant size.

In addition to my colleagues comments, It seems as if you are focusing on the high profile implants only. If you consider the moderate plus implants, you can achieve a 12 cm fill with a lower volume implant, if that is your preference. Before sheduling surgery, you should feel comfortable with your choice of implant size.

Otto Joseph Placik, MD
Chicago Plastic Surgeon
4.9 out of 5 stars 72 reviews

Choosing styles of breast implants

As Dr. Aldea has said, you will have the fewest complications if you use smaller rather than larger implants. Unless you definitely want the "look" of a high profile implant, you could certainly use a moderate (most natural) or moderate plus (slightly fuller in the upper pole than natural) and easily use the full 12 cm width without looking too big. Unless you use the best width for your body, you will run the risk of having too much space in the middle.

Breast implant sizing

Thank you for your question and for sharing your photo. Size of the implants can be very personal choices that a patient makes. In many cases, patients can go from a A cup to a D cup or larger. In our practice, I begin by asking whether you are looking for more projection or perkiness and whether you mind have some of the breast tissue push outwards on the side. In addition, I ask you to try on different external sizers to give you a sense of what your breast may look like and the feel of extra volume in the breasts. In addition, I take details measurements of the breast including the base diameter of the breast. Your volume range and the breast shape preferences helps me the further guide you in your implant selection and to give you guidance on what the breast might look. If you find that you really like the 375-400 range and this gives you the look that you are looking for, then I would stay in that range.
I would visit with some board certified plastic surgeons in your area to discuss your options and goals in more detail.


It is very difficult to determine 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 350 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. . 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 below link.


Breast implant sizing

Patient anatomy is a guide to choosing an implant shape and volume. If you have a breast diameter of 12 cms, than you have many choices. Go with the volume you want and align the implant type with your dimensions.

Steven Wallach, MD
New York Plastic Surgeon
4.1 out of 5 stars 24 reviews

Don't get bogged down in breast implant dimensions

I'm a little concerned that you are getting too bogged down in technicalities and numbers, rather than volume and form. I've read several of the answers above, and I have a little different perspective.

My postoperative results are usually aimed toward a natural appearance that shows off your body form rather than the implants themselves. I tend to use implants that are a little narrower than your breast diameter, and I offer my patients a range of implants based on volume rather than exact measurements.

I find it most important to use sizers in brassieres, with your clothes draped over to approximate the look you are looking for. This is much more important than millimeters of width. The implant itself will lie in various positions and orientations in the pocket that your plastic surgeon makes, depending on multiple conditions including your position- upright, lying down, etc...a few millimeters either way is unimportant when the implants are in place.

What is most important is the volume that is added to your breast, and that you are happy with your expectations.

Many options available for breast implant size selection

Time, weight and gravity are not on your side. Remember that the larger the implant and the weaker the surrounding support tissues the more problems you can expect over the years. A slightly more narrow implant will not make any difference with your final outcome but using a larger sized implant than desired will. Shape and base diameter are much more important than absolute implant volume. You are wise to educate yourself on the many options and use some common sense when selecting your best option.

Jeffrey Zwiren, MD
Atlanta Plastic Surgeon
4.5 out of 5 stars 16 reviews

Choosing a breast implant size

You will be fine with the 375 cc. It's only 3 mm smaller than your base width, and I've found it's better to be a little narrower than wider with implants. Also, Allergan's Natrelle line of implants run narrower overall than Mentor's implants, so you might consider a Natrelle implant. It would likely allow you to have a 339 cc or 371 cc implant and still be within a good range for your base width.

Carmen Kavali, MD
Atlanta Plastic Surgeon
4.5 out of 5 stars 38 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.