[Teddy]

I have tried some bra size calculators and looked all kinds of conversion tables for different countries and regions. Even if the consensus is that the bra size consists of band size and cup size it is very difficult to compare those "codes". I will look only standard EU and US codes and skip Chinese and Spanish and other weird variants.

I take my own boobs as an example. I live in Sweden, so I would like to use EU standard size definitions. Today I have measured a band size of 100 cm, and over bus I measured 110 cm, which in a EU-table gives me size 95B ( https://www.evasintimates.com/blog/eu-bra-sizes/ ). Well, then I open a quite well known bra size calculator at https://www.calculator.net/bra-size-calculator.html and type in my measurements. The result was US size 40C , in other words band size was as I expected, but cup size is C instead of B. On top of that, the same calculator claims I'm EU size 90E! It must be a bug.

OK, let's try another online calculator: https://www.omnicalculator.com/everyday-life/bra-size
Now I am told to be US size 42C or European 100AA!

Well, let's try third one, https://goodcalculators.com/bra-size-calculator/
It must be good, if we believe the site's name  
Now I got US size 40D and EU size 90D . I disagree, I'm not a masochist, and that band size is not comfortable.

In reality I feel bra marked as 95B, and in some cases 95A, to be quite comfortable, bit depending on variations among factories and brands. If we assume then that B cup is same on EU and US markets, my size would be US 42B - which makes sense. I bought that size bra from Temu, and it fits pretty well.

Regarding those calculators' recommendations:
Band EU 90 (US:40) feels too tight on me (or I can't even close the band without putting on an extender piece), and a cup size larger than B is too big for me with those measures (100/110 cm). I haven't tried 100AA, and it would be quite challenging to find in any shop, I believe as it is difficult enough o have good selection on 95B. 

Because my boobs seem still to be growing bigger, my bra size is likely also increasing over time. But that's not helping the issue with those calculators. They will any way strongly disagree with each other and give very confusing results.

My conclusion is that the whole thing with "standards" is bit messy, and especially those online calculators are very unreliable.

Anybody having comments?

[Beth14]

I found the same thing. That’s why I went and got fitted. Best thing I ever did. Bras are comfortable and keep me firm

[HelloDiDi]

There is no standard. Every manufacturer has their own ideas, some conversion charts make it a bit easier to navigate but even that wont really solve it. Then there's a thing nobody ever talks about, breast shape. And with bras, this comes to cup shape, cup depth wire width, wire shape, wire depth and the list goes on. There's far more variables than just cup volume only... And people still believe the idiotic myth that "anything above DD is cow tits from my favourite hentai".  

I have found the British sizing most realiable to make actual sense into things. The double lettering is a good idea, helps to make sense to it. I don't even think in Euro sizes anymore because EU sizing does not have my size listed or manufactured at all. Closest thing to that would be Ewa Michalak but they have their own sizing system too which complicates things even further.

And breast shape, I don't want to tell people my bra size because they don't understand what shape does. Wide root and shallow projection make them look smaller, but they look obviously very wide. EVERYBODY perceives narrow and projected breasts bigger than wide and shallow, every. person. alive. Unless they're well in the know of breast anatomy, shape differences and their effect to perception.

Also another myth I fucking hate with a passion is the "universal cup size myth". Meaning that people think that all A, B, C, D, etc. cups are the same. They don't understand that the letter is a ratio, not volume.

I so much wish there would be some type of universal agreed upon sizing system, but that wont ever happen as every country and every manufacturer keeps on making them on their own standards. Reality is that bras should always be custom made, just like shoes should be because no pair of breasts are the same.

[Teddy]

Thank you all, well described.

I'm not even dreaming that there could be a perfect standard coding of such a complex shape and size matching and even taking in consideration the fact, that we all are constructed somewhat differently, material properties used vary etc.

However, I have been educated and working as an engineer, and know something about standardization, and also complications of fitting stuff to numeric values  in our 3-dimensional world. I am sure that identifying sizes could be possible to do better. Much, much better than today, but I don't dream of 100% perfect system in a complex world having so many variables. A good coding standard would at least give better starting point for finding the right size and fit. Current situation is especially bad when doing online shopping. It is even an environmental issue because sending back and changing sizes adds CO2 emissions.

I have at least in the end succeeded to find bras which fit on me, and starting to better understand the chaos. And those online calculators seem to be quite useless and confusing the situation even more.

-Teddy

[wee2er]

I too am an engineer (electronic & mechanical) and see the benefits and problems of standardisation. Wouldn't it be good if there was some form of ISO EN / BS / ANSI standards for bras, but alas there isn't.

Granted like we all know volume, shape, width etc are all different on each and every one of us, so maybe it's no wonder that there isn't a standard.
Somewhere there's data saying that c.80%(?) of women wear the wrong bra size to, so its completely trial and error for everyone.

Personally, I don't find wired bras comfy at all so never wear them, instead I only wear padded soft bra tops which are far more forgiving, comfy and are a perfect fit for my B/C cups.

I think the best we will ever get is a vaguely standardised sizing like dress sizes, but admittedly even those vary wildly across manufacturers to. 
Which leaves us with the only real solutions being - keep trying on and see what fits incurring all the time/money/CO penalties, go get measured professionally or go made to measure which is more expensive but stands a far better chance of getting a bra that meets your needs.

[Teddy]

I too am an engineer (electronic & mechanical) and see the benefits and problems of standardisation. Wouldn't it be good if there was some form of ISO EN / BS / ANSI standards for bras, but alas there isn't
....[a lot removed]...

Actually there seems to be a standard for all kinds of clothing, inclusive bras: ISO-8559 series. I found some draft versions for free (The released ones are costly!).

However, after some informal research I found a rule-of-thumb way of finding the starting point for actual fitting.
1. Measure the circumference "band size" under bust and "bust size" over the boobs.
2. Round the band size in Metric system downward to nearest 5cm, or in Imperial system downward to nearest even number. That is the Band Size number
3. Calculate "Bust Size" - "Band Size" difference. The result is then rounded downward to nearest 5cm / 2 inches. Calculated and rounded difference 0 would be AA, 5 cm/2" A, 10 cm/4" is B etc. The size system for the result is EU/International.

That method should work reasonably well according to my very limited studies, and give a meaningful indication from which sizes to start fitting. I guess the needs caused of varying shape and support requirements are increasing with breast size, so quite possibly for about D cup and bigger only the band size indication is close to final fit. I have not had an opportunity to verify that calculation method with big breasts because I still carry quite small ones, according to the algorithm to be "B size"

[HelloDiDi]

Interesting observation about bra size calculations I've noted is that bigger I'be grown, the calculators keep getting more accurate. Especially abrathatfits.org which I think is the best as its easy to swap between sizing systems. But often I seem to need to compensate one cup size down which I think is due to my breast shape, that got easier after the first fat graft which added fullness in middle and top which do not show on tape, so measurements changed very little, but the calculation became more accurate. I'm expecting this to happen again on second fat graft, but this time my measurements are more likely to change as there will be additional outer fullness also.

Seems like there's less need to compensate for chest and back now. My back used to be quite wide but muscle loss and liposuction have too it the other way so there's less everything else and more breast which comes closer to typical bra design as they all seem to think that most women have narrow and projected breasts. Business aims to averages which sucks for someone with my bra fitting problems. I need wide wires, big cups but without crazy depth. Its not helping that my size is beyond typical selection now, with some luck I might still find something frmo UK shops but its unilikely and next bra will be from Poland with yet another sizing system.

I don't mind as long as I just find something that fits well enough. I'm most of the time braless anyway. Maybe not good for my neck and back, but I like the freedom as supportive bras are anxiety inducing torture devices more than comfy clothing. It really isn't super nice because support means that they're snug too.

[wee2er]

Actually there seems to be a standard for all kinds of clothing, inclusive bras: ISO-8559 series. I found some draft versions for free (The released ones are costly!).

However, after some informal research I found a rule-of-thumb way of finding the starting point for actual fitting.
1. Measure the circumference "band size" under bust and "bust size" over the boobs.
2. Round the band size in Metric system downward to nearest 5cm, or in Imperial system downward to nearest even number. That is the Band Size number
3. Calculate "Bust Size" - "Band Size" difference. The result is then rounded downward to nearest 5cm / 2 inches. Calculated and rounded difference 0 would be AA, 5 cm/2" A, 10 cm/4" is B etc. The size system for the result is EU/International.

That method should work reasonably well according to my very limited studies, and give a meaningful indication from which sizes to start fitting. I guess the needs caused of varying shape and support requirements are increasing with breast size, so quite possibly for about D cup and bigger only the band size indication is close to final fit. I have not had an opportunity to verify that calculation method with big breasts because I still carry quite small ones, according to the algorithm to be "B size"

OMG, knew I should have searched ISO before commenting..... many thanks for being a proper engineer and doing the research first. good ole ISO 8559, a bit of bed time reading LOL

[Toni68!]

I have come to praise Victoria Secret. When I wanted to start wearing a Bra they helped me with the correct size a 36 B. When it became uncomfortable they fitted me with a 36C. The were very professional and a great help. It has taken me a while and a few different styles to get to the one that current wear is a pushup bra. One of the sales ladies help me because I am a C cup but my breast are still growing and are not full enough to fill a C cup bra at the top of the bra. The pushup fixes that. Plus it gives me cleavage I did have.

[Beth14]

Victoria’s Secret doesn’t fit me well at all. Glad you like them.