How big will I be with 400cc?

Hello and thank you for your question.  The
best advice you can receive is from an in-person consultation.  It is difficult to determine if a 400cc implant will be the right size for you without an in-person examination.  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.  
Best wishes and good luck.
Richard G. Reish, M.D.
Harvard-trained plastic surgeon

Thank you for sharing your excellent question.  Because each brand of bra manufacturers sizes their garments differently it is impossible to guarantee a particular band size or cup size for patients prior to surgery.  Additionally there is no direct correlation between implant cc size and a bra size.  I would recommend seeing an ASPS board certified plastic surgeon for an in-person discussion.  They are in the best position to ensure that the implants the two of your decide upon are the right ones to meet your expectations.  It sounds as if it may be wise for you to "try on" several of the implants so that you can have a better visual representation as to what they would look like.  Best wishes!

Unfortunately none will know just how big you will be with a 400cc implant. We probably can say though you will reach a full D cup if this is your goal. Will you like the look? The best way is to show your surgeon what you expect, photos, sizers, to help get things right.

Thank you for the question.   There is no accurate/reliable/predictable correlation between size/profile breast implant utilized and cup size achieved. For example, I do not think that the generalizations of "200 cc equates to 1 cup" hold any validity or are helpful in any specific or practical way.  In my practice, I ask patients not to communicate their goals, or evaluate the outcome of the procedure performed, based on cup size references.
Ultimately, careful selection of plastic surgeon and 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 "small 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 (and the attached link, dedicated to breast augmentation surgery concerns) helps. Best wishes. 

Congratulations on your decision to have breast augmentation.  Bra size is very difficult to predict because different manufacturers and retailers labeled the same bra different sizes.   The 400 cc breast implant in my opinion  is a large implant but with the proper breast base width can look very nice.Your best option is to be examined by a plastic surgeon who can provide you with breast implant sizers to be placed into a bra so that you can see and feel what that volume looks and feels like on your body. To learn more about breast implant sizing please read below:

One of the more frequent questions I'm asked as an aesthetic plastic surgeon for patients considering breast implants is "how do I know what size, and shape I need?” The answer to this question has changed dramatically throughout the 25 years that I've been doing breast augmentation. I've also learned that the words that patients used to describe either what they want or don't want can be completely misleading into what I interpret their meaning to be. Therefore, I like to request that our patients considering breast augmentation bring in photos of both what they think they like and what they don't like. There seems to be a multitude of sources on the Internet where these photos can be downloaded. By looking at the patient's desires, I get a better understanding of what they want. We no longer recommend that we place the exact implant on top of the existing breasts and then place a stretchy bra over it to give us any idea what that exact same implant under the muscle would produce in size. That method, in my opinion, will always over represent what the actual result will be. If you are going to use a sizing type method, then Mentor makes a shell sizing system such that, when the shell size corresponding to the implant that it represents is placed over the existing breast and in a bra, it will better represent what that size implant under the breast and muscle will look like. We've also used 3-D imaging called Vectra® since its inception some 6 to 7 years ago. With this method, a three-dimensional photograph of the actual patient is taken and can be seen on a large screen television by both the physician and perspective breast augmentation patient at the same time. We then can place all of the different implants that are available under that image and decide what size, shape, fill ratio, and height to base width relationships will look best for each patient. Silicone gel breast implants come basically into shapes either round or shaped. They also come with either a textured or smooth surface. In my mind, there are advantages and disadvantages of every scenario and combination of those choices. Most of the time a round smooth implant placed under the muscle works very well for breast augmentation patients. It's then very simple to just look at size and ratio projection to base width and select the perfect implant for that patients shape and desire. Sometimes we would like to use a textured surface implant. Here the advantages are that the textured surface implants tend to migrate less in the pocket, as there is some frictional resistance to motion. Another advantage of textured implants is that the capsular contracture rate, especially when implants put above the muscle, is less than for smooth wall implants. Shaped implants, because we do not want them to turn in the pocket, are always textured. My planning method to optimize the best implant for each patient is begun with a measurement of the base width of the breast. We would then like to subtract about a centimeter and a half total off of that number so as to have coverage of breast tissue over the implant. We then will have a range of implants whose base width matches that number. If we go larger than that number, which sometimes patients will want, we as plastic surgeons know that these larger implants can have more problems down the line. For instance, larger implants may migrate below the crease which one has to lower at the time of surgery in order to get the implant in. When these implants migrate below the natural crease, they can create a second crease in what we call a "double bubble". Large implants can also; because of the pressure they put on the overlying breast tissue, thin that tissue out such that there is less overlying breast tissue over the implant as time passes. After we have the base width, our next decision needs to be what is the ratio of the base width to the projection of the implant. Essentially, there are usually four choices ranging from fairly flat which is called low-profile, to progressively more height and less width with the same volume of silicone gel, which is called ultrahigh profile. There are two profiles in between which are the ones more commonly used and these are called moderate profile and moderate profile plus. Common scenarios in which taller implants would be desired may be in patients who want a larger look than their natural base with would allow or have a fair amount of loose overlying skin that were trying to hold up. For patients who want a more natural look, a moderate profile or moderate profile plus shape is more desirable. There are also anatomically shaped implants. Rather than being around these implants can either be taller than they are wide or wider than they are tall. There are good reasons in patients to use either. For instance, in the patient's with very widely spaced breasts and a large breastbone, a shaped implant that's wider than it is tall can help hide that a little bit. Another example of the patient in who a shaped implant would be best, is that patient with laxity after childbirth or weight loss. When the nipple is just at the level of the inframammary crease, we can sometimes get away with a tall implant that is anatomically shaped such that the nipple when is it at the lower two thirds of the breast mound created by the implant still looks good and natural and may obviate the need for a breast lift. By spending some time, long before the operation takes place, using the Vectra® 3-D imaging method, we can decide what type, shape, and ratio of width to height would best serve the patient's needs. We can then avoid what is sometimes done which is the placement of sizers at the time of surgery. These sizers, in my opinion, have a few negative implications. One is that there is a cost inherent in using them and usually multiple ones are needed to make a decision as to which implant would look best. I also believe that placing sizers in and out of the breast pocket can be traumatic to that pocket and can cause bleeding. For me, the state-of-the-art in today's breast augmentation is to decide long before the operation exactly which implant would look best using computer animation. A new wrinkle into the choice of breast implants is that breast implants now come with silicone gel that is filled to a higher volume in the shell where it is placed. This will allow for a round smooth implant, for instance to collapse less in the upright position mimicking more of the look of the shaped implant. When patients show me a photo of a very rounded upper part her breast, I would likely choose one of these higher volumes implants such as the Natrelle Inspira® silicone gel breast implant. Often times patients will present with breasts that are of different sizes. One of the options to correct this is to use breast implants of different sizes in order to best create symmetry. One of the newer methods to help in symmetry creation is to do what we call a hybrid breast augmentation. In the hybrid breast augmentation, the patient who has asymmetry of the breast to begin can have matching silicone gel implants placed and the overlying breast tissue can be made to look the same in volume and shape by using fat grafting. In that way, no matter what the change in weight of the patient is over time, the breast is more likely to have the same or similar size. When it comes to symmetry, I like to tell our patients that they should consider their breasts to be sisters that live across the railroad tracks from each other rather than twins. With proper preoperative planning and flawless execution of breast augmentation, this can be one of the most satisfying aesthetic plastic surgery outcomes for both patients and physicians.