What Cup Size Will 400/425cc Make Me If I'm A 34B Now?

I'm 27 years old, 5'11 and weigh 133lbs. I have small 34B cups currently (although I'm always surprised I wear B cup bras as they seem more like As to me). I am thinking of going for high profile gel implants, 400cc on one side and 425cc on the other to improve symmetry. What cup size would I be after this?

Doctor Answers 15

Cup size after breast augmentation

Thank you for your question. Unfortunately, cup size following breast augmentation surgery is not an exact science as there is no standardization of cup sizes between manufacturers.  Different manufacturers have different cup volumes and as the chest size increases so does the cup size,  which is to say that a 38 B cup is larger than a 34 B cup.  To further complicate matters the final cup size will also be influenced by your rib cage shape, breast width, shape of your breast, laxity of the skin, bulk of the pectoralis muscle, etc. You can see how this can get quite complicated. As a general rule of thumb with a 34 size bra each cup size is around150 cc. So if you are truly a 34 chest ( as measured around your chest just under your arms but above your breasts) you should expect to go up three cup sizes with 400 cc implants. 

So what is the best way to determine breast cup size?

There are many different approaches to this dilemma.  Some surgeons make the decision at the time of surgery by placing different implants into the patient to determine the appropriate size. The only problem with this is that the patient is not actively involved in the process and has to rely on preoperative  photo review of other patients to determine the size. This can be  difficult as no two patients  breasts are exactly the same size and shape.    I prefer  to have my patients actively involved in sizing before surgery.  I have patient obtain a underwire bra of the size they would like to be.  They then come into the office and we try different size implants to determine what will fill the bra appropriately.  When the final size has been determined an additional 30 cc is added to account for the bra itself.  Using this technique I have found that patients satisfaction with the size of implants  has been very significantly improved.


San Francisco Plastic Surgeon
5.0 out of 5 stars 8 reviews

Have a question? Ask a doctor

Sizing by cc's

I agree with Dr. DeMars and his statement is a good way to put it. You will be 400-425 cc's bigger. If you put on a size 10 gown you will look like you with a size 10 gown on. Another way to think of it is if you were talking to an orthopedic surgeon and asked how you'd look with a 50 cm hip implant. I strongly disagree with Dr. Greenwald that you can figure it out in the OR and the patient gets whatever the surgeon thought looked good in OR conditions. 

We have enough experience today to know that breast implants have more leeway than hip implants but the y must be fitted/sized for what works and looks natural or gives a predictable outcome with a low chance of the unexpected or unwanted. In general, this means making sure that the width (same as height in a round implants) matches the base width of your breast upright, and then choose a low, medium, or high forward profile/projection depending on roughly increasing by a cup, cup-and-a-half, or two cup bra sizes from what you started with (which isn't measurable exactly before or after) and relative to your chest around (which doesn't change). You can then look up the dimensions on the chart of available saline-filled or gel-filled implants and find out how many cc's that comes to. Saline-filled implants allow for about a 10% different volume for the same width but an increased volume in gel-filled means a wider implant which doesn't usually help with symmetry. 

The thing is to start with the measurements, apparent size, and desired goal and work up to the volume rather than the other way around. 

Scott L. Replogle, MD
Denver Plastic Surgeon
4.0 out of 5 stars 1 review

Cup size

No one can guarantee what cup size you will be with a certain implant online.  There are too many variables as you mentioned you are not too sure what cup size you even are now.   Even different manufacturers of bra's can not agree.  My patients tell me that Victoria Secrets bra's are usually one or even two cup sizes different than some other brands.  You need to look at pictures with your surgeon to decide on the look that you want and then in my practice I use a temporary sizer in the OR to make the final implant size decision.  Most importantly, make sure you are seeing a board certified plastic surgeon as there are a lot of imposters out there willing to take your money.

Gary Hall,MD

Gary Hall, MD
Kansas City Plastic Surgeon
4.5 out of 5 stars 30 reviews

Breast Implant Size Prediction

Predicting cup size after breast implant placement is far from an exact science. There are many factors that go into how any size implant will look on one's chest not to mention the variable of how any woman interprets what she is seeing and what size she thinks it is. The best that anyone can predict is that you will be somewhere in the C/D range but, quite frankly, that projection is not that helpful to you. You need to sit down with your plastic surgeon and show pictures of breast sizes that you like and go through a sizing exercise. While there can never be a completely accurate prediction, this type of discussion with your surgeon will help make your more comfortable with your size selection.  

Implant Size

Those implants will make you 400-425 cc bigger than you are now. But without knowing how big you are now, breast width, rib projection, thickness and position of the muscles and thickness and location of the breast tissue and degreee of elasticity and firmness of the skin it would be impossible to com up with a cup size. It's a very complex issue. I tell my patients to forget about cup size since not even the bra manufacturers can agre on that. Surgery has never been designed to make a cup size. It creates a look and a proportion. Show your surgeon pictures of what you like and don't like and let him worry about how many ccs that will take.You are hiring him for results. It would not be expected that you could do a better job of picking implants than he can since he has years of experience doing that.

Ronald V. DeMars, MD
Portland Plastic Surgeon
5.0 out of 5 stars 15 reviews

Breast Augmentation cup sizes

Cup sizes vary from different manufacturing company. You may be 34B cup size from one brand and 36A with another brand. Therefore, cup sizes are not a predictable outcome. In general, the estimated assessment is that one cup size is like 100 -150cc volume. Therefore, you may end up being C or D cup size depending on what brand you choose. How I determine what size implant would be appropriate for you is taking your breast diameter measurement, which give us a good determination  what size implant to choose. . Next, what profile of the implants will depends on how much projection you wish to have. High profile will give you more anterior projection, whereas moderate profile will give you more of the natural slope projection.

Kim-Chi Vu, MD
Portland Plastic Surgeon
5.0 out of 5 stars 2 reviews

Breast Cup Size after Breast Augmentation?

Thank you for the question.

As you mentioned,  cup sizes always difficult to determine depending on the person and the specific bra manufacturer.

Likewise,  there is no direct correlation between  the size of breast implants  and the resulting cup size.

In planning your breast augmentation procedure it will be very important to communicate your size goals with your surgeon.  in my practice I find the use of goal pictures to be very helpful.  in your case you could use your own before breast-feeding pictures as the goal. I have found that the use of words such as “natural” or “C cup” or "fake looking" or "top heavy" means different things to different people and therefore prove unhelpful.

Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup  size may also be inaccurate.

I use  intraoperative sizers and place the patient in the upright position to evaluate breast size. Use of these sizers also allow me to select the breast implant profile (low, moderate, moderate plus, high-profile) that would most likely achieve the patient's goals. The patient's goal pictures are hanging on the wall, and allow for direct comparison.
I have found that this system is very helpful in improving the chances of achieving the patient's goals as consistently as possible. 
By the way, the most common regret after this operation, is “I wish I was bigger”.

I hope this helps.

What cup size will 400/425cc make me if I'm a 34B now?

Hello! Thank you for your question. In general, implant size does not correlate with bra cup size. The cup size itself will vary from manufacturer to manufacturer as well as who is doing the actual measurements. Thus, cup size is never a reliable indicator for your breast size. I typically encourage my patients not to communicate her desires in cup size but more on the actual look and appearance. Given your desires, a breast augmentation, with an implant or fat grafting, would be an ideal procedure that would meet your expectations. Breast augmentation is now the most popular procedure performed in plastic surgery today. One tolerated very well by women with minimal downtime and high patient satisfaction.

Good communication between you and your surgeon of your expectations is warranted - choosing your surgeon wisely is the first step. Discussion of your wishes and having an honest and open dialog of your procedure is mandatory (e.g, implant type, incision, placement, etc). Your height, weight, breast width, and body habitus will make a difference for which implant style/projection to choose. Implant profile will also make a difference on the projection, which will influence overall breast/cup size. I have found that photographs brought by the patient is helpful to get a visualization of the appearance you wish for in terms of size, shape, fullness, etc. In addition, your surgeon's pre and postoperative photographs should demonstrate a realistic goal for you of results. Sizers are helpful during an in-office consultation. Once this has been accomplished, allow your surgeon to utilize his/her best medical judgment during the procedure to finesse the best possible result for you after preoperative biodimensional planning and fitting the right implant for your breast width. This is the most important determinant for the sizing of implants, which will provide the optimal result and most aesthetically-pleasing result for you.

Consult with a board-certified plastic surgeon well-versed in breast procedures who will examine and discuss with you the various options and factors to consider and help you decide which one will be the right one for you. Hope me that this helps! Best wishes for a wonderful result!

Lewis Albert Andres, MD
Scottsdale Plastic Surgeon
5.0 out of 5 stars 13 reviews


There is no way to guarantee a particular bra size. Bra sizing varies greatly between bra manufacturers and a C in one bra will be a D in another. What matters more than the assigned bra size is the way the implant looks on you. The best option for your body and aesthetic goals can be determined in a thorough implant sizing session.

Implant sizing depends on several factors. One of the most important factors is your breast width. Generally, your surgeon will measure your breast width, and then provide you with a range of implant sizes appropriate for your native breast size. There are more nuances to it than just what I've described, but this approach works for most women.

I usually have my patients bring in a large bra and a tight t-shirt to do sizing. I'll then choose 3-4 implants that I feel are appropriate, and have my patients place them in the bra under the tight t-shirt. My patients can then look in the mirror and get a good sense of what they will look like with the provided implant sizes. My patients like this approach and get a great idea of how they will look.

By using this technique, your surgeon can outline a range of appropriate implant sizes that will be aesthetically pleasing, and you make the final decision.

I hope this helps. Good luck!


Asif Pirani, MD, FRCS(C)
Toronto Plastic Surgeon
5.0 out of 5 stars 30 reviews

Cup Size and Breast Implants

It is very difficult to predict what cup size you will be after your procedure.  Cup sizes are not standardized.  So a D cup in one designer could be a C cup or B cup in another designer.   This is the approach I use to help guide my patients with their implant size selection:

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. However, there are some limitations of what size we can recommend. For instance, some implants may just be too big for a narrow chest wall. Your surgeon can review this with you during the consultation.

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.  If you have decided on saline implants, then based on the gel sizer you select, we can guide you to the saline implant that achieves a similar look.
Hope this helps.
Dr. Basu
Houston, TX

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.