What’s the deal with bra sizes anyway?

Hello Ladies,

For a few weeks now, I contemplated the ongoing confusion plaguing the millions of women searching for a bra that fits—confusion due in part to the persistent misinformation circulating the web.  However, until now, I have been so busy working at the shop that I was unable to give the issue the time and attention it deserves.

At the end of May, Jockey made waves in the lingerie world by launching a new fit kit which tosses out the band/cup combo of old in favor of a band measurement paired with a series of breast molds used to identify the best cup volume for you.  Women were promised a simple solution for their bra woes although many were left scratching their heads at sizes like 2-32 or 5-36.  For more information on the sizing system itself, read these comprehensive reviews from Sweet Nothings, Ali Cudby, and Elizabeth Dale.

In addition to Jockey’s system, intrepid bra shoppers can turn to the expansive and resourceful reditt /ABraThatFits which addresses sizing and fit issues on a massive, interrelated, and somewhat jumbled scale only made possible by the Internet.  Finally, there is always the advice found on manufacturer’s and retailer’s websites.  Of course, if you pick ten different guides and compare the advice, often you will find varying and sometimes conflicting ways of measuring, a limited explanation of why that method is the best, and/or not even a cursory examination on how to ensure the suggested size actually works for you.

Jockey's promotional picture for the kit.
Jockey’s promotional picture for the kit.

This confusion has led Jezebel writers (among others) to ponder whether bras actually come from outer space because the garment most women wear seems to baffle just about everyone, and the lingerie industry keeps piling on layer upon layer of complexity.  So, what’s the deal with bra sizes?  Are they the result of some conspiratorially complex code only Robert Langdon can unravel?  Or is there a simpler way of figuring things out?

MemeLet’s start with band size.  We recommend breathing normally and measuring your underbust with a soft tape measure, keeping it level around the torso and pulling firmly but not tightly.  Why?  Most modern brands cut the band to fit that measurement, meaning the average 32 band is designed to accommodate a ribcage measuring approximately 32″.  Consequently, if you add inches to the initial measurement, you may buy a band intended for a woman proportionally bigger than you.  With the larger band, the rest of the bra is usually scaled for the bigger frame, including the length and shape of the underwires, the height and width of the center gore, and the position of the straps on the cups.  The resulting shape change may not work well for your figure.

Women with narrow ribcages and less padding and/or smaller busts may find a band in their actual ribcage measurement is too tight.  Because the ribs have less padding, the pressure of the underwire and the elastic band can feel binding and painful.  Bumping up a single band size can alleviate the problem although some women prefer to move up two band sizes. Another potential reason to size up is if you do not require much support from the bra and want to keep the band from stretching too much on a daily basis.  As an example, both The Lingerie Lesbian and The Lingerie Addict add inches onto their band size.

Having explained the exception, I still recommend testing your initial band size first and then deciding whether a larger size would work better.  For instance, if your starting point band is a 28, try it before jumping right to a 32.  For every woman who fits the profile of someone who would add inches, there is another who would rather have a tighter band.  Like all clothing items, some things come down to personal preference.

Resident blogger Dezi, for example, prefers to wear a 30E or F instead of a 32DD or 34D.
Resident blogger Dezi, for example, prefers to wear a 30E or F instead of a 32DD or 34D.

Now that we have a band size, we will examine cup size.  Since the band component represents the torso, all cup size does is relate the volume of your breasts to the size of your band.  As the band scales by proportion, the cup sizes alerts the manufacturer to how much breast tissue you have relative to that band size.  This is why cup sizes mean nothing without the band size.  A woman who wears a 30D has proportionally the same size breasts as a woman wearing a 38D, i.e., both women have bust measurements approximately 4″ larger than their ribcage measurements; however, the woman wearing a 30D has significantly less breast volume.  In fact, a 38D bra has the same breast volume as a 30FF!

A 28G Cleo Jude in the foreground with sister size 34E in the background
A 28G Cleo Jude in the foreground with sister size 34E in the background

To find your cup size, stand upright and use the soft tape to measure around the fullest part of your bust, pulling the tape loosely.  You do not want to compress any breast tissue with this measurement.

Subtract your band size from the bust measurement and use a chart like the one below to find the corresponding cup size:

Measurement (in.) US Size UK Size
1 A A
2 B B
3 C C
4 D D
7 G F
8 H FF
9 I G
10 J GG
11 K H
12 L HH
13 M J
14 N JJ
15 O K
16 KK

Our bra size calculator is available to use as well.  If you’re between cup sizes, I recommend starting with the larger one first, but again this is only a starting point size.  In certain styles you may need to size down in the cup while others require moving up.

As I mentioned in my post on our calculator, another way of determining your cup size involves measuring the bust while bending over at the waist.  Even though some women report a more accurate size with this method, I cannot recommend the technique over the one above as I have dealt with several returns through our online store from people who bought cup sizes way too large based on the bending over method.  Others recommend averaging the two measurements; however, if you have no idea what size to buy, start with the upright measurement and use the good fit criteria to judge whether you need a larger cup size.

Once you have a general idea about your bra size, the rest becomes a trial-and-error process based on what styles you like and how a manufacturer designs a bra.  Some bras, no matter what size you try, will not work for your breast shape.  In fact, entire lines from a manufacturer may be at odds with your figure because the fit model they use differs too much from your shape.  For example, my struggles with Curvy Kate have been well-documented.  The design of the bras is wider and shallower than my breast shape allows, and as a result, nothing seems to fit properly.  Meanwhile, I have better luck with Cleo by Panache which features narrower underwires and deeper cups.

Despite the added headache to the bra shopping experience, it’s actually a good thing manufacturers utilize different cuts so that the diversity of women’s bodies can be better represented.  Since most brands keep the same model in mind, you may decide to stick with a brand you know works for you.

After discussing the issues with sizing and styles, a natural question arises:  If I have a size, how do I know which styles will work for me?  That’s a question which deserves a separate post where I have more time to explore how breast shape and bra style relate.  In the meantime, here are some great resources from the very talented, passionate bra bloggers:  Bras I Hate & Love Full on Top vs Full on Bottom, Venusian Glow, Fussy Busty Wire Shape Guide, Bra Naked Truth.



What’s the deal with bra sizes anyway?
Erica is a lover all things lingerie and is passionate about helping people find the bra which fits and flatters. Side passions include reading, writing, hiking, dairy-free food, walking her Jack Russell terrorists, and dying her hair everything from black to red.

7 thoughts on “What’s the deal with bra sizes anyway?

  • July 19, 2013 at 7:05 pm

    I’ve noticed when trying US brand bras they seem to run smaller in the cup than they should…meaning if I’m in a 38F/FF UK I should be able to wear most 38G/H US bras (that are similar, you know what I mean..). But what I’m finding is I need an I cup US (if I could ever find it, which I can’t…).

    So, I’m sized out of almost all brands that use US sizing. Is there something more to the fit difference between US and UK sizing than band and cup size?

    • Erica
      July 20, 2013 at 9:59 am

      I actually wrote a blog on this: http://sophisticatedpair.com/blog/?p=2507 Basically, the short answer is: There’s as much variation in cup size in US brands as there is in UK brands. There’s just no standardization, so sometimes you might be totally sized out of a brand which should fit while in other cases you need to drop a cup size. Wacoal, for example, has a couple of styles which cut at least a cup size bigger than UK brands (their Retro Chic and Awareness underwire bra come mind) while others are a bit smaller (the Embrace Lace Contour Bra). Then, to add to the confusion, a lot of US brands are using UK sizing now (like Parfait). Bra sizing can be a total mess sometimes!

      • July 20, 2013 at 10:31 am

        I can’t wear Wacoal at all- their wires are too U shaped (and I am not). I did try the Awareness bra (have been meaning to do a review) and I couldn’t really gauge the cup size because the shape was so incompatible with my shape. I do agree it was “large”, though!

        More often than not I run into the too small cup problem in US sized brands. It’s rather discouraging. There’s something about the way they cut most of them – and I can’t help but wonder if they’re purposely designing them so the band overlaps the cup area?

        I need to go read your other post, don’t I?????

        • Erica
          July 20, 2013 at 11:02 am

          Wacoal does have a more U-Shaped design for sure. Not to mention, I remember you said you need gores lower than 3″ right? Most of their styles in H cups have higher center gores (some quite high indeed!), and as a result, they still wouldn’t be the best for you. However, for others curious about the US/UK sizing differences, it’s good to know that the inconsistencies can be pretty standard . . . well, maybe “good” isn’t quite the right word. 😀

          • July 20, 2013 at 11:10 am

            Yes, the Awareness is a whole lotta bra. Everywhere.

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