I wrote about why I had a serious problem with bras back in April. Now, we’re Bra Theory, a small team in NYC dedicated to saving the world from bad bras. We take a mathematical approach — and there’s some 3D stuff involved, too!

Last week was Bra Theory’s one year anniversary, and we are happy to share that after one year, we finally have it: one bra that fits one person.

We know, we know. You’re probably thinking, “One year? One person?! …and do you really need all that math for a bra?”

…Or maybe not.

Maybe you’ve been thinking all along that you’re a multidimensional human being with multidimensional boobs, which can’t possibly be described in a two measurements like 34B.

Maybe you’ve been secretly wishing that you didn’t have to compromise between a bra that doesn’t bother you, a bra that provides enough support, and time spent trying on bras that could be spent elsewhere in your life— that you could have something that fits and does heavy-lifting if necessary, all without spending hours in the fitting room.

We’re here to check in with you and let you know: you’re not the only one. We hear you, and we’ve decided to do something about it. We want to solve your problems with bras.

We’re going for the moonshot.

Here are the problems you — and all of us — probably have with bras, and what we’ve been doing about it for the past year ( — and if you’re suffering bra woes that we haven’t mentioned below, please share so we can get on the case!) Stick around until the end to see our moonshot bra.

Problems you probably have with bras, and what we‘re doing about it

Problem 1. Your underwires like to stab you in the back, side, front, and everywhere.

Formula for underwire troubles = same under-bust circumference in blue + same over-bust circumference in pink + different distribution of breast tissue in yellow + one set of wires for them all

Here’s how the industry currently categorizes boobs in fitting rooms: two measurements, over the bust and under the bust. All of the boobs above will measure to the same size. Only one will survive the underwire.

This is because the shape of your breast root, where breast tissue begins and your rib cage ends, matters. Underwires don’t have to hurt. In fact, they help by directing the tension in a bra, so long as they’re not sitting on something they shouldn’t be.

Boobs, unfortunately, are less malleable than cats. That, or cardboard boxes are more forgiving than underwires. Credit: /u/pzycho

When deciding the piece of steel hardware that encircles your breasts for at least eight hours a day, you need more than two measurements. You deserve more than two measurements.

Our approach? Take a lot of measurements and start narrowing them down.

Don’t you want to channel your own Han Solo?

We still have a lot to figure out, like how to map the root on pendulous breasts or bodies with less defined roots. Some roots aren’t semicircular at all — whereas most underwires are! — and probably need a custom wire solution.

Until we find a solution for root-to-underwire, please have a conversation with your roots today and ask:

How are you, Roots? Do you like this bra?

If not today, do your boobs a favor the next time you find yourself rushing to take off your bra. Check for red marks — that’s usually where the metal sits on you all day — and see if it’s soft tissue or rib cage. They’ll thank you one day.

Problem 2. You can’t fit your orange into a glass.

Bra-fit enthusiast /u/t_maia described this syndrome as “orange-in-a-glass”.

One bra might not fit one pair of breasts not because the volume or wire isn’t right, but because the cups were built for another shape altogether.

More than two dimensions matter. You deserve your orange modeled in 3D, in all its glory, whatever it looks like.

We know your boobs probably don’t look like the first, second, and third from the left. Boobs are complex, beautiful creatures, elusive to your attempts to mathematically define them.

In the process of trying to model the boob, we discovered that a lot more matters in the quest for your holy grail— curvature, elasticity, malleability, only to name a few. We’ll probably need a physics engine to fully answer this question, which is a pretty exciting thing to break open since boob physics has thus far been mainly developed for video game breasts.

While we’re working on it, take note: if your boob becomes a quad-boob or gapes at the top of the cup, know that it’s not necessarily a story of volume. There’s a lot of reasons behind your cup looking funny, and it all comes down to not capturing your unique 3D shape.

Always remember: it’s not you, and it’s not even necessarily the bra. It’s the bra not being designed for you.

Problem 3. Your bras force you to ask the everlasting question: do you want to feel supported, or do you want to be able to breathe?

You need a band that supports without restricting your ability to breathe or eat, and to do that, you need to solve some physics problems.

A bra needs enough tension in the band elastic to produce the effect of a cantilever.

Your bra should be firm enough to produce the effect of a cantilever. But you, like all human beings, probably want to breathe, because you are not a cantilever. You don’t want a bra bolted into your rib cage.

Our approach was to find a Goldilocks solution that’s just right. We ran some tests and discovered that we like 15 Newtons of force on a snug, supportive band. That’s like someone giving you a really warm hug.

If you want to try replicating it, you can grab a spring scale and your favorite bra and do this at home! Let us know your results. 15 Newtons is definitely not for everyone. Some of us like it tighter; some of us like it looser. If you have less mass, you likely need less firmness in the band to support the force of the mass downward on the fabric, and can afford to breathe a little.

Problem 4. Let’s say all of that works, and you have a bra that fits — and only fits.

There’s more to life than fit. There’s function, too. The whole reason why we wear bras is because they’re a highly functional piece in our wardrobe that helps support and stabilize otherwise mobile breast tissue, as well as shape malleable breast tissue into whatever shape our heart desires.

Here’s a demonstration of why it’s important that “fit” becomes “function.”

What was once a docile hat, is now a badass bra.

Still, it’s not entirely clear what the shaping function of a bra is. We can talk about the “ideal boob shape” all we want, but it’s different for everyone.

Maybe you want minimization. Maybe you want max cleavage. Maybe you want duck-billed. Maybe you’re happy with a secure boob hat for everyday life. Maybe you want a rounded silhouette.

Our approach right now? When boobs go low, we go high.

So far, we’ve managed (1) Ice Cream Cone and (2) Rounded. It looks pretty great in a t-shirt, but pretty funny from the side.

Ice cream or Rounded with a hint of gravity? You decide!

There are complicating factors, of course, like how much your boob will fight fabric to sit where it wants to sit. Our ice cream cone was an attempt to maximize lift, but at some point, something’s gotta give. Our rounded silhouette compromised for more fullness on the bottom of the breast, where it happened to sit best on our fit model.

We believe that the world would be a better place if everyone were the writer of her own bra destiny. So think about it: in a perfect fitting, functional bra, what’s your ideal silhouette? Let us know in the comments below!

Problem 5. Your bra seems to fit! — until you start speed-walking or going down staircases.

We like to think of this concept as the “watermelon in a spandex bag” problem, first introduced by Beverly Johnson, the fairy bra mother. We bring to you a seasonally-themed reproduction of this experiment: A Squash in Spandex Bag.

Setup for Squash in Spandex Experiment: rigid white fabric, stretchy black fabric, and squash.

Conclusion: your bra needs enough structural integrity to withstand anything that’s thrown at it. When all else fails, the fabric of the bra should stay in place. A bra that does not fit in motion, does not fit.

You’d think it wouldn’t matter, especially for those of us with smaller breasts — but power-walking and staircases can be a trying experience. That being said, one of our top priorities is to design a bra with enough structural integrity to help you with the vicissitudes of life.

We proudly rock our #bellyjelly! But we don’t have boob bounce, because sometimes that’s uncomfortable and our boobs want some support. Bra Theory on the left, Other Bra on the right.

Problem 6. Even you didn’t have any of the (99) bra problems above, there’s more to a bra than fit and function.

There’s more to a bra than fit and function. You can’t have it feel like sandpaper, and sometimes you want to look pretty or sexy or confident in a bra, and that involves some aesthetic flair.

This is what we call “Prototype Fashion”, or when we run out of fabrics and start hustling. Would you wear this?

Still, regardless of your aesthetic preferences in a bra, we have a theory.

Our guess, our theory, is that we mean what we say when we say that all we want is a bra that fits and functions (and doesn’t feel like sandpaper). And until something meets our most basic needs in a bra, as much as we can like feeling sexy or pretty or special in silk or laces on occasion, we first and foremost want something for ourselves: a bra where we can be ourselves.

There’s a Maslow’s Hierarchy of Boobs, and we have to start with the foundation. The order may differ from person to person, but we need foundational needs to be met before we can reach boob actualization.

We’ve been building that bra since November 2015, keeping in mind all the problems above with bras that we’ve mentioned (and then some). We’ve gone through a lot of prototypes…

and ended up with one bra that fits one real person.

And you know what? We kind of like it. It may show through a see-through shirt (white shows our mistakes the best, which lets us iterate the fastest), but what we call Bra Theory possesses a pureness of spirit and function.

Here’s what we experienced with a bra that finally fits.

The feeling it gave, I think, is what we want to aim for — it felt like the temperature of a room when the heater is set just right. It felt like the touch of someone you love who you aren’t conscious of because they’re so familiar, and feel so right. It felt like I was home, in my body.

Thank you for sharing your problems with bras back in April when we first embarked on this mission. Thank you, today, for sharing this year with us. Many thanks to the many people who sent us feedback on our mission, the industry professionals who gave us the time of day when we came to them with a moonshot, and the lovely folks at the Bra Making Forum, the open-source bra-making community.

We’re back to getting heads down into problem-solving so that we can build more bras for more people. If your boobs happen to be available in NYC for measurement, send an email to mona@bratheory.com.

Feeling strong, safe, sexy, and all those wonderful feelings from Boob Actualization.

We want to hear from you!

There are loads of things we don’t know about boobs or bras because we don’t talk about them that often. We’d love to hear more about your unique needs in a bra! Feel free to leave a response to this post, or email mona@bratheory.com.

  1. What problems do you have with your bras? Are we missing any?
  2. How firm do you like the tension in your band?
  3. What’s your ideal silhouette in a bra?
  4. What are your fundamental aesthetic needs in a bra? Is “Prototype Fashion” good enough?
  5. Anything else?

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And if you’re in pain right now and on the search for a bra, check out http://www.reddit.com/r/abrathatfits.


Why I have a problem with bras and what I’m going to do about it.

I have a serious problem with bras.

Unfortunately, for half of the population, this problem isn’t easily understood. This is understandable. We don’t really talk about boobs, so if you don’t have a pair of your own, it can be hard to relate.

If you fall into this category, bear with me and try this exercise.

We could all use a little practice in empathy, and what better way to understand others than to imagine yourself in someone else’s shoes–or in this case, bra?

(As for the other half of the population, let’s see if this sounds about right to you.)

Imagine that you have boobs.

They bounce when you move and they are in a constant fight against gravity. They are topped with this thing called the “nipple,” and to some it is a cardinal sin for the fabled “nipple” to show itself in public. They also look awesome!

But you are expected, if not required, to put on an article of clothing that:

  1. Hides your nipples
  2. Provides a rounded, lifted shape (this expectation varies with time, but you live in 2016 when bullet bras are not as in vogue)
  3. Does not show seams, bulges, or wrinkles

Still, aesthetics is a preference, with a normative standard set by examples you see in TV, movies, and pornography. And you don’t have to follow those standards! In terms of aesthetics, the world is your oyster mermaid-shell bra. For example:


You could rock the bullet bra.

You might even want to show off your nipples because why not?


If Batman can do it, so can you!

But no matter your aesthetic preference for shape and style, you also have your own set of functional expectations for a bra:

  1. You would like your bra to at the least stabilize the movement of your breasts
  2. You would like the bra to do this without extraneous movement of its own

This is because you know the consequences if your chosen bra doesn’t fit. 

Best-case scenario: mild embarrassment, discomfort, or distraction in the form of muffin-top-like boob spillage, strap sliding, etc.

Worst-case scenario: sternum pain because there is a metal underwire giving you a hug all day (imagine if Batman had a breastplate whose metal grooves dug into his pectoralis major), neck pain, back pain, etc.

For better or worse, you want a bra that maybe shapes, maybe lifts, but definitely fits.

Now imagine that it’s been four years since you last purchased a bra.

You’re down to your last ill-fitting, graying bra from your last shopping excursion.

There’s a reason for that.

Remember that the last time you went shopping for bras, you spent an hour of your life trying on bra after bra, in a fitting room with the decor of a “sexy jail cell” 1


Photo and “sexy jail” quote credit: Kristin Chirico for Buzzfeed

A fit specialist lassoed you twice with a tape measurer and proclaimed you 34B. Your first 34B made your boobs look like this from the side:


An empty space in the cup means that the cup is too big. Size down to a 32B.


There’s excess double boob spilling over the top. Does that mean the cup is too small?

Was the bra too big, or too small? What does that even mean? 

You didn’t know.

All you knew was that you had tried on bras for an hour–alternately shoving yourself into things until you got the equivalent of boob muffin-top or feeling inadequate in the gaping maws of a cup. Every so often, it was punctuated by a cheerful, “May I come in?” from the hallway, and always when your boobs were halfway into or and out of cups.

In the end, you bought a single bra and wore it for four years straight until it finally gave up against gravity and time.

Okay, by now you’ve been through enough.

You can stop imagining yourself in a bra. (That is, unless you wear one, and go through this every four years.)

Whew, doesn’t that feel better? (That’s how a lot of us feel at the end of the day.)

The fallacy of “too big” and “too small”

Boobs are a little more complicated than “small” and “big”.

A fit specialist might tell you to size up for a bra, like getting a baggier T-shirt if the tighter one doesn’t fit right.

The theory behind sizing up goes something like this: an orange might not fit into a martini glass, but it’ll fit into a bowl.2 So can’t you just size up?


The short answer is: no.

Bras function best when they’re an exact fit. You wouldn’t be very happy if you could only get shoes in sizes Small, Medium, and Large.

If you wouldn’t shove your feet into a general solution, you wouldn’t want to shove your boobs into a general solution, either. Breast tissue is malleable, but your sternum isn’t.

Wait! But we use two parameters, like 34B.

Let’s think about that for a second. The band size parameter, 34, refers to the circumference under the bust. The cup size parameter, B, refers to the difference between your full bust and under bust measurement.

These are busts that can be classified as 34B. In these diagrams, the blue circle measures to 34″ and the pink circle measures to 36″.


Cross-sectional view from top down. Blue indicates under bust measurement, pink indicates full bust measurement, and yellow represents actual breast tissue distribution.

Imagine that we try to put this 34B bra onto them all.

32C with bra.png

If you happen to match what brands think is the median bust, congratulations! You’ve hit the bra jackpot. Otherwise…ouch.

So… why are people talking about bras in terms of one dimension, like “too big” or “too small”?

Why are people even talking about bras in terms of two dimensions, like 34B?

Isn’t the thing… three dimensional? Aren’t YOU a three-dimensional being?

And that’s my problem with bras.

People are complex. Boobs are complex, with a lot of variations along the possible parameters:

  • Rib cage angle between top of boob to bottom of boob
  • Rib cage softness
  • Position of boob on rib cage in the vertical axis
  • Position of boob on rib cage in the horizontal axis
  • Separation between boobs
  • Width of each breast root, where it is attached to rib cage (anywhere between underarm and sternum)
  • Height of each breast root, where it is attached to the rib cage (anywhere between collarbone and abdomen)
  • Projection of tissue
  • Tissue density
  • Shoulder width

In the 1970s, North American bra manufacturers and industry professionals attempted to convene and put a stop to the madness of not having a universal standard. They came away without a system.3

Can you guess why?

It’s the same reason why a lingerie store doesn’t have enough stock to address the entire population (and the same reason a pharmacy doesn’t sell prescription glasses). If each of the above 10 variables can be described on a scale of 1 to N, we end up with N^10 bra combinations.

So it turns out that this is a really hard problem.

There are too many boobs in the world, with more variations than two variables can account for.

Even if we could define bra sizes with a bunch of variables like root width and height, how can you collect this data with a user experience that is non-invasive, quick, and accurate? Imagine this:

“Hello there, welcome to Bra Jail. Let me measure your tissue density”.



The current solution

We live in a world where we squeeze our chests into a N x M matrix of available bras. Of course, the beauty of boobs is that the softness of tissue moderates the difficulty of fitting a bra. But for many, N x M is not enough.

In response, lingerie brands have been recognizing the need for more bras and more sizes. In recent years the bra matrix of 32-38, A-DDD has added many more sizes: 2840 or letters through K

The industry’s answer is more numbers, more letters. With this solution, variations in what sizes mean is actually a good thing because customers can try different brands to get different fits. It makes sense, right? If enough lingerie brands start designing for different demographics, we’ll eventually have enough saturation in the market such that all types of shapes and sizes are provided for.

In other words, today’s solution is to have lots of bras and variability.

Do you see the one major problem with this solution?

The onus is still on the people to find a bra that fits, which involves trying on bra after bra in the fitting room, not knowing all the variables to the problem.

How do you match bras to customers when we don’t have the terminology to talk about it? Do brands even signal to their customers what shape and size they cater to? Can you imagine a Lingerie Store turning you away at the door, telling you that they don’t stock your size of 26F? Or is it more likely that the store will measure you to a size that they do stock?

It wouldn’t be so bad if more people understood that N x M doesn’t provide for everyone. But what does it mean to a young woman, when she doesn’t fit into anything at a store? What is she to do, but think that she is “weird”, or that her boobs are “weird”?

Today, people have to figure it out themselves, armed with only one number and a few letters.

An entire community of women and men have rallied on Reddit’s /r/abrathatfits to provide a more accurate size calculator, measurement guides, shape guides, store guides, recommendations, and fit checks to anyone on their search for a bra that fits.

You can find bra whisperers who work their magic in places that look like Ollivander’s wand shop. Also known as boob witches and bra fairies, these experts will be able to tell you your size in the specific brand and model that will fit you, given your shape–no measuring tape required.

But finding a bra shouldn’t require wizardry.

For many, finding a bra fits can still take over 100 tries. My own journey included over forty bras to find bras that fit.

The Bra Tax is real.

And we deserve more than that.

This is where Bra Theory comes in

I started this journey where you probably began.

How hard can it be to find a bra?

It couldn’t be that bad. So I did my homework and found the online calculators. Forty bras later, I realized that there was more to bra-fitting than met the eye. The above is only the tip of the iceberg. We haven’t even gotten to the fun technical stuff that drives everyone bonkers, like differences in sizing by country (30DDD in the United States = 30E in the UK = 30F in France) or relative cup sizing (volume of a 30C = 32B = 34A, volume of a 30C < 32C < 34C).

I used to feel pretty miffed about it. Now, I feel bad for the industry professionals who, years ago, tried to convene and decide how to better represent size and shape. They probably sat together, thought about all the complexities of boobs, and said:


That’s how I felt too.

I found myself saying,

“It’s one of those problems that you want someone else to solve because it’s too hard.”

But that’s exactly the type of problem that deserves attention.

In November of 2015, I left my job as a software engineer at Switch, a mobile application that helps people find jobs, to help people find better-fitting bras. I’ve spent the last five months 3d-modeling boobs and engineering a bra that fits me. It involves a lot of math.

I have researched the status quo of bra-fitting in the industry today, visited bra whisperers, subjected myself to a lot of sexy jails, talked with industry professionals, and learned how to sew.

I’ve learned a lot on this journey towards a better bra solution, and I thought–hey, this knowledge is worth sharing. So without further ado:

This is Bra Theory, an empathetic and mathematical approach to bras.

The goal of Bra Theory is to understand someone’s bust with more precision and empathy than two standards of measurement, to celebrate the complexities of the boob, and to construct a bra that fits you instead of an industry size.

Screen Shot 2016-03-28 at 1.31.21 PM.png

Bra Theory will cover

  • problem-solving
  • the physics of bras
  • mathematical solutions to netting a curved solid
  • an outsider’s look at the fashion industry today
  • fun articles about bras
  • entrepreneurship
  • and more.

This is Bra Theory.

Bra math

And this is where you come in

If you had to imagine yourself in a bra for the majority of this blog post, kudos! If you wear a bra, N^10 times more kudos! 

If you liked what you read,

  1. Subscribe for future updates about bra engineering
  2. Share what you’ve learned (and be empathetic while you share).
  3. Get educated about bras with the good people at /r/abrathatfits.
  4. Contribute your bra specs to Bratabase, or if you feel comfortable, the Breast Shapes Gallery that shows non-sexualized, everyday boobs.

Thanks for the read, and for the practice in empathy.

This is a problem that we might trivialize because it’s about boobs, but let’s face it–this is a very real problem, and real problems deserve solutions.

Let’s solve bras!

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  1. “No one can figure out my bra size.” http://www.buzzfeed.com/kristinchirico/no-one-can-figure-out-my-bra-size.
  2. t_maia. “The bras in my supposed size fit weird, and I’m not sure why. Help?” Reddit, 2013. https://www.reddit.com/r/ABraThatFits/comments/15skno/the_bras_in_my_supposed_size_fit_weird_and_im_not/c7phuxw.
  3. Johnson, Beverly. The Bra-makers Manual: A professional approach to bra design, draft, fit and construction. Hamilton, Ontario: Turtle Press, 2005.