How do you know what size you'll be after a breast reduction?
December 20, 2022
May 3, 2023
By Dr. Andrew Campbell-Lloyd

How do you know what size you'll be after a breast reduction?

Every operation I do involves a certain amount of trust from my patients. Whilst I can describe the operations I do (pretty well I think), and I can explain how we plan and execute the surgery (also pretty well), there is always an element of the unknown when it comes to one aspect of the outcome for many women: what cup size will I be after surgery?

This is a central question to the procedures I perform - implant revision, implant removal, breast reconstruction...but perhaps most significantly, breast reduction.

For patients having breast reduction surgery, the SIZE of the breast is what drives women to seek that surgery, and their size after surgery is in many ways the main outcome that determines satisfaction. With the other procedures I do, size matters, but changes in the size of the breast are generally a consequence of a decision to have surgery for other reasons.

So, how do we consider and manage breast size (and patients' expectations) before and during surgery?

There are multiple elements that contribute to a woman's perception of her breast size. Each of these elements may be significant on their own, but it is the collective assessment of these features that is relevant when we are considering breast reduction.

Cup Size

The first thing to think about, because it is the most common way we consider breast size, is the bra cup. This may seem like the easiest way to assess the breast, and therefore the easiest way to convey information about breast size, but in reality this is far from true.

The problem with cup size is the lack of standardisation of what a given cup size means, and how it translates into what a woman experiences.

Because of variations between brands, styles, and measuring techniques, cup size is probably the least useful way of discussing breast size, but ultimately we always end up discussing both expectations and outcomes in cup sizes.

The thing that is worth thinking about is how we can offer a relatively accurate translation from different measures of breast volume back into cup size.

The reality is that most women with a larger bust are wearing the wrong sized bra. Why? Because it is bloody hard to get correctly fitted if you have a big bust, and even harder to buy bras, especially for women with a slim chest and a disproportionately large bust. So the answer for many ladies is to increase the chest measurement to allow a smaller cup size. We often see ladies who wear something like a 14E, when in reality they should be wearing a 12G....but where the hell do you find a 12G bra??

So why does that work? What does a cup size really mean?

Basically, cup size measures the addition of the breast on top of a basic chest circumference (typically measured under the bust). So if you measure the chest and you're a size 12, then you measure around the chest to include the breasts, the additional circumference provides the cup size. Add 1 inch to the chest measurement, you have an A cup. 2 inches, a B. 3 inches, a C and so on. Given both the simplicity and the fallibility of that formula you can start to see where cup size falls apart as a useful measure. But its simplicity and ubiquity is what brings us back to cup size at the end of the day

Volume & weight

So let's consider what a cup size then means in terms of volume. This is something that surgeons have looked at over the years, and in a very approximate way, a cup size is something around 125-150cc with each increment if we take an average chest measurement. This metric is very rough, and in reality the size difference between cup sizes changes both as we go up in cup size, and as we go up in chest measurement. So the difference for example between a B and C cup may be around 100cc, but the difference between a DD and E cup could be 160cc, and between an E and F cup over 200cc. We also have some relatively useful data that tells us that breast density is just under 1g/cc. The value of knowing this information is that we then have a rough translation between the weight of tissue we remove during a breast reduction operation, and the volume that represents, and hence, the change in cup size. For example, to go from a size 14F to a 14C would require that we remove over 600g of tissue.

Whilst we can now create some sort of relationship between the cup size, weight and volume of the breast, there are two other essential aspects of the breast that we use to determine both what is an appropriate amount of breast tissue to remove, and what the impact of removing it will be.


Position refers to how and where the breast sits in its unsupported state, relative to the rest of the chest. We can consider this from the perspective of the breast "boundaries", and the degree of excess tissue beyond those anatomical limits.

The breast is in some respects defined by 3 clear boundaries. Toward the centre of the chest, the inner boundary of the breast is what we could consider the cleavage. Under the breast, the inframammary crease defines the lower extent of the breast and is the determinant of how high or low on the chest the breast sits. The outer boundary of the breast is the one that tends to get a little blurry, as it can sometimes merge into the flank and the under-arm area (many ladies complain of the feeling of excess breadth of the breast as the breast extends around the side, and this contributes to poor fit in a standard underwire bra as the wire digs in ) and in some respects this lateral boundary requires recreation for many ladies having a breast reduction.

When we consider a patient for breast reduction, we look at how those boundaries are preserved, or lost, and with particular reference the the inframammary breast crease, we consider the degree of overhanging breast tissue (also referred to as ptosis) and the extent to which the breast skin rests on abdominal skin.


The final item to tick off is proportion. Proportion is the most subjective, but equally it is often the "measure" we rely on most when actually performing breast reduction procedures. Proportion (when it comes to the breast) may be in the eye of the beholder but there are a few ways I try to make it a slightly more robust, reliable measure of our end goal in breast reduction.

We can arbitrarily consider the "proportionate" breast to meet 2 main criteria:

  • the breast tissue should sit above the breast crease;
  • the width of the breast (when viewed from the front) should not visibly extend beyond the edge of the chest.
What is rather interesting is that using those two very basic metrics to guide how we shape a breast during a breast reduction procedure, we will nearly always create a breast that falls within a range from C cup to D cup for most women.

Whilst performing a breast reduction there are a couple of basic manoeuvres that are necessary to ensure that I can meet the two criteria I have mentioned. Firstly, when planning the surgery, I aim to narrow the breast substantially in most cases to ensure that the width of the breast is appropriate.

breast reduction operative markings
An example of typical breast reduction operative "markings". You can see lines forming a triangle of sorts on each breast. As these lines come together (after the tissue between is removed), this creates the narrowing effect of a breast reduction.

This narrowing is vital in itself, but the narrowing is also the mechanism we use to "suspend" the breast in its new elevated position. Secondly, I use an "internal bra" technique in all breast reduction cases to lock the scar into the crease, and to stabilise the position of the breast crease which creates further support for the lower part of the breast.

These two concepts ensure that the question of proportion is managed.

Putting it all together

My job, when I talk about and perform breast reduction surgery, is to ensure my patients know firstly what is possible and secondly that they'll get what they want. As with most of what I do, it comes back to expectation management.

For most women, they have the ability to choose somewhere along a limited spectrum of outcomes from breast reduction. We can, whilst meeting the requirement for proportionality, offer them an outcome that sits between two extremes, depending on their desires. Some ladies will ask me to make them "as small as possible", whilst others will prefer to maintain some fullness, often for fear of how they will feel with a dramatically smaller bust having lived their entire lives with large breasts. Most women just want to be proportionate.

What this introduces is the idea of the limits of breast reduction surgery. On the one hand, the upper limit of size is mostly determined by a combination of proportion and a desire for a meaningful change in breast size - if we fail to reduce the size of the breast sufficiently, we have performed nothing more than a breast lift...which is a different concept entirely in many ways, and we shouldn't pretend that one can be the other, not least because that can result in the totally inappropriate use of item numbers (which as another article entirely, but possibly one worth writing).

On the other hand, the lower limit of size is determined by the necessity to preserve the parts of the breast we want, and the parts we need to rebuild a smaller, better shaped breast. That can be a slightly tricky concept to convey to a patient, so one way to think of it is this: the bits of the breast we want to keep need a blood supply. So in order to safely reduce and then rebuild the breast, we are forced to keep certain parts of the breast largely untouched to preserve that blood supply. This then determines the lower limit of size.

Between those two limits, there is the potential for choice.

Ultimately, it is important that patients understand that I cannot guarantee a particular cup size with breast reduction. The breast will always be smaller, we will always adhere to our rules of proportionality, and we will do our best to push the outcome along the spectrum in whatever way the patient wishes. And generally this will result in a breast size that is comfortable, aesthetically pleasing, and appropriate. Something I see very often is that patients will go down in the band size (eg. from a 14 to a 12) after surgery, for the simple reason that they are now able to buy a cup size, off the rack, in their correct chest measurement, which they couldn't have done before surgery. So this can mean someone starts off wearing a 14F, and ends up wearing a 12D despite having a 600g reduction.

Breast reduction surgery offers both a more comfortable appearance, and an enormous functional improvement. So in many ways the exact cup size that the breast is reduced to becomes largely irrelevant!

Get in touch if you have any questions.