Three Numbers, One Cup

Alright, so this is something that has been bouncing about in the back of my head for a while.  I learned what an FBA (full bust adjustment) was about six months ago.  This may have revolutionized my sewing, because it made me really start to really consider fit.  I know there are many people who open an envelope pattern, choose a size, and make a perfectly fitting garment.  On the flip side, there are those of us who toggle between three sizes, make all sorts of crazy adjustments, and end up with pattern that are more tape than paper, but usually also end up with clothes that fit better than anything we could find in a store.  I know all of my projects have been more successful since I have been thinking about swaybacks and FBS, and with such care going into the fitting of my clothes, I ponder having proper undergarments now more than ever before.  And I came to the conclusion that they really don’t fit right, and that I probably need to remedy this situation.

Perhaps, first, a little story about why I started questioning my bras.  I suppose the real start of all of this was the fault of Tim Gunn.  Although the show no longer runs, I was a follower of Tim Gunn’s Guide to Style.  On his show, Tim took a lady, analyzed her body shape with help of computer software, and told her what styles would flatter her body.  After looking through some (sad) wardrobes, a few pieces would head to the tailor’s shop, and most would go out the window.  The woman got some serious $$$, and a day with Tim Gunn to go out and search for the 10 basic items (dress, white button down, skirt, pants, jeans, trench, etc.).  Usually the first stop was a bra shop where Tim would leave it in the hands of the professionals.  There was one episode where a woman who was not as full up top as I was ended up in the same size bra that I was wearing.  That started the inkling that maybe things were not quite right in my underwear drawer.  But, well, I sort of filed that away and didn’t think about it too much after that, but the doubt was still there.  Then, a few years later, a more personal event made me start to re-question things.

One day I am in front of the class, giving instruction, pointing to stuff on the blackboard and my boobs fall out – under my bra!  This was a bra I had gotten when I was sick, and had been having the opposite problem with them falling out over the top of the cups at that time.  Measuring the circumference around the fullest part of the bust, nothing had changed.  The problem was I was losing weight from my back.  Now, I don’t know about the general audience, but I never really learned what the bra sizing meant.  I mean, I knew A was smaller than B smaller than C, and clearly a 32 is smaller than a 38, but other than that, not much of an idea.  I assumed that the number referred to the full bust number (which I knew, from being measured for skating costumes), and the letter was something to play around with.  Before that a bra was something embarrassing you sent your mom to get because you didn’t want the store clerks to see you buying one.  So really, I had never given it much thought.  Actually, if I hadn’t started sewing, I probably still wouldn’t have given it any thought.  In any case, I ponder why they don’t teach you things like this in school – it is useful knowledge and would probably save so much time and money spent on back pain that shouldn’t occur in the first place.  But I digress.

In any case, after the slippage incident and the more recent revelation of the FBA, I went on a quest to understand bra sizing and boy howdy, what a mess that was.  Nearly every article will tell you that 85-90% of women are wearing the wrong bra size.  Almost none of them tell you how to fix it.  Most of the articles that tell you how to measure are based on sizing from the 1930s(!!!), before many of the modern construction materials were made or used.  Based on reading about FBAs for sewing, I knew those had to be wrong.  So, after much searching I finally found a (few) sources that discussed modern fitting and how to measure for bra sizing.

Alright, so for sewing people, we know that we need to measure UPPER BUST (just under the armpits, trying to keep measuring tape as horizontal as possible) and FULL BUST (at the largest part of the bust, also horizontal tape measure).  Really, you should have a friend help you if at all possible.  In addition, you want to wear what you consider the best fitting bra you have – wearing different bras can drastically affect the upper bust measurement.  An ill fitting bra lets your busts drop, and gives too small of an upper bust measurement.  The other number you need is the UNDER BUST (around the top of the ribs, right under the busts).

Let’s use some real numbers for examples:
Upper bust (upb) = 34″
Full bust (fb) = 37″
Under bust (udb) = 31″

Pattern Adjustments
Alright, so now we have 3 bust measurements.  When we buy a pattern (that doesn’t come with cup size adjustments), it is sized for a B size cup.  Well, what is a B sized cup?  Assuming that your bra size is incorrect (remember, we have an 85% chance of being wrong), how do you really know your cup size?  If we have the measurements, it doesn’t really matter what size bra you are wearing, we will have to calculate the clothing cup sizes anyway (and, as you will see, it might be different from your bra cup size anyway).  We only care about how much to adjust the pattern here, so we need to find out how much to do that.  What we are interested in is the difference between the numbers.  For sewing patterns, the most common method is to use upper bust and full bust.  Then use this formula:

fb – upb = cup

If you have a 1″ difference, you have an A cup, 2″ = B, 3″ = C, etc.  So, let’s take our example numbers:

37 – 34 = 3″ = C cup.

However, I think a better method (especailly if you have more than a 2″ difference between upper and under bust sizes) is to use an average of the upper and under bust.  For example,

(34″ + 31″)/2 = 32.5″, which rounds up to 33″

37″ – 33″ = 4″ = D cup

In either case, we have to do an FBA.  I think for something very fitted, I would try the C cup size (with a muslin), but for something like a coat maybe adjust to a D cup size.  I won’t go into detail about how to do that in this post (it depends on the pattern style), but it is widely available in many sewing books and online resources.  I may cover it in a later post.

Measuring for a bra (the WRONG way)
Ok, so as I mentioned, many internet websites have bra size information or a bra calculator based on sizing from the 1930s.  This is WRONG, but is is good to know/understand how it is wrong, so you don’t get stuck with a poorly fitted bra or a poorly trained sales person (not to name names, but I know Victoria’s secret: she is stuck in the 1930s).

Ok, so back in the day, this is how it was done: you measure the under bust.  Then you use the following handy table:

-if udb < 31" add +5"
-if udb > 33″ add +3″

So, for our example, we have udb = 31″ so we add 5″.  We now have a band size (bs) of 36″.

Next, you measure the full bust.  Then subtract band size from full bust:

fb – bs = cup

We again have the 1″=A, 2″=B, etc.

37″ – 36″ = 1″ = A cup

An A cup!?!?!?!  We just did a FULL bust adjustment, and now you say we need to wear an A cup bra???  Clearly, this makes no sense.  Back in the days before elastic bands, the need for ease in the bra would have been understandable.  But today?  Not so much.

Measuring for a bra (the RIGHT way)
Alright, so clearly the previous method doesn’t make sense.  Really, the problem is that we don’t need to add so much extra to the band size.  A better method is to round to the nearest even number.  So for our example, 31″ rounds to a 32″ size band.

Now we again use the fb – bs = cup:

37″ – 32″ = 5″ = DD cup size.

So here we discovered that we should be wearing a 32DD bra size.  Of course, trying the bra on is critically important.  Different styles and different manufacturers will make things that fit slightly differently.  You want the band to fit horizontal around your body.  You want you bust apex halfway between the shoulder and the elbow.  You don’t want spillage over the top (cups are too small) or puckering/bending of the cups (either cups too big, or, more likely, band is too big and cups are too far apart).  And you want the bra to be snug on the loosest setting (as you wear it, the elastic stretches and then you go to tighter settings).  If these things are not correct, try a different band or cup size.  The rule of thumb: if you go up a band size, go down a cup size, and vice versa.  So, for example, if we tried the 32DD and it was way too tight, we would try a 34D in the same style.  Bras are like jeans – there are many styles and sizes, and it will take a bit of effort to find a good one.  However, unlike RTW jeans where sizing is rather arbitrary, we can have some idea of bra sizing before we get to a shop.

Here is a great article about bra sizing: article!

Buying a bra: The issues…
Alright, so now we know a little about our bra size.  The problem now – finding a 32DD!  I suspect most women who measure themselves will find they need smaller bands and bigger cups.  Sadly, if you go into a less expensive store (read: Target, WalMart, etc.) you aren’t going to find a 32DD.  Period.  Typically their sizing runs something like 30-34A, 32-38B, 34-40C, 36-42D, 40-48DD, regardless of brand.  I mean, the band sizing on those DDs would slide over my hips, so it is a bit of a worldview shift to start contemplating DD sizing.  Sadly, since this sizing is difficult (impossible) to find for cheaper brands, it probably means I need to consider saving up to invest in a new undergarment wardrobe.  I have tried an experiment with going down a band size/up a cup size and I am quite please with the results (in very many ways).  I do not think the fit is perfect yet, but I do think it is a significant improvement.

I was pondering where to find these non-typical sizes.  Victoria’s Secret has precious few styles in the 32DD size range.  Frederick’s has far more options, and may be a go-to store in the future.  Also, for those ladies with really big sizing problems, I found this website:

Bravissimo!  They carry many (many) sizes and even substantial sports bras.  Sadly, they are UK based, so ordering internationally could be a bit expensive.  The website has some good fitting information as well.

So, I suppose the lesson from all of this is it is important to find information, question sources, and think a little bit for yourself.  Also, finding a good bra is hard work.  In any case, I encourage the ladies: know your numbers!

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