All About Bra Fitting: Bust Position and Torso Shape

For part three of my informal exploration into the elements of bra fit, I want to look at bust position and torso shape. A lot of bra advice focuses on the breast itself, and while that is hugely important, the torso that provides the base for the breast can have a dramatic effect on fit and comfort, too.

Since bra manufacturers are attempting to sell their design bra to as many people as possible, they have to settle on one averaged sizing standard that hopefully (sort of) fits as many of their customers as possible as a basis for their bra designs. As anyone who sews knows, it’s hard to fit a wide range of bodies with a specific sizing standard without the fit being off somewhere for most people, which is why patterns rarely fit perfectly right out of the envelope. The proportions of certain body measurements like back torso width to front torso width, breast diameter, and breast spacing can vary widely between women, but for production purposes for any given bra brand, there are only a single, averaged set of measures being used, unless the brand specializes in a particular subset of body types (petite, curvy, tall, plus sizes).

What this means is that if you have body proportions that differ dramatically from that standard, you may have certain fit problems. A simple, very common fit issue happens when bust spacing is different than the assumed standard, which is one to two finger widths apart. If your breasts have less space than this or are touching in the center, underwires in a standard bra don’t rest against the sternum, but instead sit painfully on top of or jab into the breast tissue, and there may be some gaping at the outer side of the cup. (A possible solution to this is a plunge style bra or a bra with a very low, narrow gore.) If your breasts are more widely spaced than the assumed standard, this will usually mean that the cup gapes in the center front near the gore while wires jab or rest on top of the breast tissue on the outer edge of the breast. (Bras with a wider center gore can help with this, and shorter wired styles like demi bras can help with wire issues on the outside of the breast.) Some other common bust position issues arise if your breasts have a wide or narrow root (more on this in a hugely-relevant-to-this-stuff future in-depth look at breast shape), or if your back is particularly broad or narrow. Both of these may throw off the proportions of the bra wings to the cup placement, landing underwires in the wrong place relative to the breast.

But there are also other, less obvious factors of body anatomy that complicate bra fit. Overall ribcage shape, both vertically and horizontally speaking, can dramatically affect how a bra rests against the body and whether the breast tissue can then fully supported by the cups. Since the majority of a bra’s support is provided by the bra band and the cups, if these aren’t positioned in a way to effectively hold and distribute the weight of breast tissue, the bra is unlikely to offer much support or comfort. Most mass bra production uses a horizontally oval shaped, vertically gradually tapered to the waistline type of rib cage shape as their baseline for shaping the bra band and positioning bra cups within it. But, of course, not all rib cages are shaped this way.

Here’s a great illustration of rib shapes viewed from the side that comes from a site (Butterfly Collection Blog) that seems down at the moment. (I don’t agree with the shape terminology used here, because I’ve seen rib flare describe something else in other contexts, curved vs. rounded is confusing, etc, but the visual is great).

Vertically speaking, rib cages can be very straight, and barely taper to the waist at all, especially in more rectangular torso shapes without a very defined waistline. Rib cages can also be rounded or what might be called barrel chested, which means the ribs don’t taper inward toward the waistline as much as the standard but are more curved outward. Rib cages can be very dramatically tapered inward toward the waistline, especially in dramatic hourglass type shapes with a very small waist. Each of these variations will change the ratio of band to cup, and can require different adjustments to the vertical shape of the band to help it fit more closely to the body as it must in order to give adequate support..

Horizontally speaking, rib cages can have a variety of shapes other than oval that can mean the way breast tissue fills cups is different than with the standard oval shape. Here is an illustration of rib cage shapes in cross section that might help explain. It happens to be male, but you can get an idea of how breast tissue stacked on these shapes would cause breasts to project differently:

The “standard” chest has an oval shaped front and relatively flat chest wall on which the typical bra can rest evenly against the body. On a more barrel shaped chest, the chest wall is more rounded, and when a standard bra is positioned on this shape, bra cups may point outward in what is often called an east/west position. I’m not an expert on anatomy and my knowledge here is limited, but I’d expect that bodies exist in a continuum of shapes, and that the projecting rib cage (pectus carinatum) and inwardly curved rib cage (pectus excavatum) pictured here are probably extreme examples of shapes that occur to a lesser degree in plenty of people.

From what I’ve been able to find about these variations, a convex, outwardly curving front rib cage shape causes a range of fit problems because of how a bra rests against this shape and where the breast tissue is distributed relative to the resulting angle of the bra cups. Bra cups may be too far apart, with gaping at the sides and not enough fullness in the center front of the cup. Fashion Incubator has a great in depth write up on this particular shape with some illustrative pictures here.

My intuition is that with a chest wall that curves in a more concave way in front, the fit problems in a standard bra might be similar but reversed. My guess is that a standard bra would be tilted inward in a way that it would smoosh the cups together. The problem then is that the cups will be positioned differently than the breast tissue is actually distributed on the body, so there may be some gapping in the center front of the cups, and they might not be full enough to contain all the breast tissue at the sides. I suspect underwires might be especially uncomfortable in the center for this body type.

This is a lot of information and it seems a bit overwhelming, but my belief is that better fit begins with a better understanding of one’s own body shape. Knowing the physical factors that affect bra fit can help you know where to begin to look for answers. The internet has some amazing resources that deal with issues like these in depth, like Her Room, which links to recommended bra brands known to work well for specific fit issues, or Bratabase, which is a community dedicated to finding good fit and reviewing bra brands by actual wearers. There’s even a reddit community dedicated to A Bra That Fits.

I also feel like there is a huge amount of psychological baggage that comes along with bra fitting. A bra that flatters us can make us feel not only comfortable but attractive and confident. Trying on 37 bras and not ever being able to feel good about the results has this nasty way of eating away at your confidence. Never being able to find a standard bra that fit well or looked good on me for at least a decade of adulthood (along with a ton of jokes about being small chested in the era of cleavage and push up bra fashion) gave me a lot of negative feels about my appearance. Sadly, I know my experience is very, very, very common, and that no matter what shape or size they are, it’s all too easy for women (and men) to feel that there is something inferior or inadequate about their bodies. I’d like to yell it from the rooftops now that just because a person’s body doesn’t fit the “standard” doesn’t mean it’s somehow lesser or there’s something “wrong.” All fit standards are abstractions, not ideals. And even the fit “problems” I describe above aren’t “problems” so much as merely shape differences that just require style tweaks or certain adjustments in order to achieve support and comfort.

I think that’s it for today (*climbs down from favored soapbox*), but my next deep dive in bra fitting will explore the very related issue of breast shape and underwire types. (For quick reference, here are part one, Anatomy of a Bra and How to Know if a Bra Fits and part two, All About the Bra Band: It’s Cantilevered!).