We have been married for over 30 years. When we first started dating, my wife wore a 34C bra. After kids, life, and (for both of us) a little extra weight, she now wears bigger clothes.
So we were shopping together recently, and she mentioned wanting to find a new 40B wireless bra.
Here’s what I don’t get — and I’m trying not to be weird about this — but her breasts look way bigger now than when we first met. Like, noticeably fuller and larger.
I started reading about “sister sizes” and band/cup stuff, but it doesn’t make sense to me why a B cup nowlooks so much bigger than her C cup back then.
Shouldn’t the B cup be smaller? Or is there something about the way sizing works with bigger band sizes that makes it deceptive?
I am not complaining at all, my wife is awesome, regardless of her cup size, I am just genuinely confused how this works.
PS I hope I picked the right flair.
Comments
Don’t know the answer to your question but just wanted to say, thank you for being a decent person. Seriously. The bar is in hell nowadays and people like you give me faith 🙂
42 yr old female here and I just recently learned that cup sizes are based on the difference in band and breast circumference. So bc she is large band size the breasts are likely still larger than when she was smaller band and larger cup
It’s all in how cup volume scales with band size. A “B” cup on a 40 band holds more volume than a C on a 34 band, even though the letter’s smaller, the band’s bigger. So a 40B will look fuller than a 34C
It is ok if it seems confusing. Even with reading up on sister sizes it might not make sense. A lot of people do not understand even on band sizes the concept how sister sizes work on band sizes (under bust measurements) next to each other, like 40B & 38C.
So my experience is different than many but it has helped me to understand this very well because my under bust has changed quite a bit in my life naturally like you two have gone through. I experienced precocious puberty (not dwarfism) in grade school and finished puberty in 3rd/4th grade. So my growth stopped when I was 4’7” and I had an under-bust measurement of 32” (the under bust is what you know as the band size) and I wore a B cup. Today I weigh more and I wear a 40C. So I kind of bracket what your wife has gone through. I won’t deep dive into discussing Cup sizes because it has been covered so much better before. But the short version is that the cup size letter (A B C D…) is standardized regardless of the size of your under bust/band size. The cup size letter is based on how far out your breast projects from your under bust measurement. It is pretty straightforward and makes sense if you think about the visualization. If the breast is 1” larger (stick outs) from the under-bust that is an A cup. 2”=B cup, 3”=C cup, 4”=D cup 5”=DD.
Because they technically ARE bigger. The cup size is determined by the difference between the band size or underbust (circumference of her ribcage under her breasts) and the breast size (circumference around the fullest part of the breasts). 1″ difference between band and cup is an A cup, 2″ difference is a B cup, 3″ difference is a C cup, and so on. When she was a 34C, her band size (rib cage under her breasts) was 34″ and her cup size (the fullest part of her breasts) was 37″. At a 40B, the fullest part of her breasts is 42″.
This is why you shouldn’t necessarily judge someone by their cup size because my cup size is larger than hers, but her breasts are actually bigger than mine.
This page has a really helpful table showing the approximate volume of breast meant to fit each cup in a bra: https://cocorubyplasticsurgery.com.au/blog/bra-cup-sizes-and-different-breast-volumes/
In short, even though the cup label has decreased, the actual amount of breast has increased significantly. A 34C fits 29 cubic inches per breast. A 40B fits 43 cubic inches, nearly double the original amount.
To further explain, let’s break down how bra sizing works. The number is the band size in inches, i.e. the circumference of the ribs, where the bra will sit on the torso. The letter is the size of the cup, typically A-E (though it can be outside this range). You can think of these A-E letter sizes like: small, medium-small, medium, medium-large, and large.
“Sister sizes” is the idea that 2 bras with different band sizes can fit the same way if you go up or down one cup size. So for instance, a 34C would (in theory) fit the same way as a 32D (smaller band, bigger cup) or a 36B (bigger band, smaller cup).
So to compare your listed sizes:
34C = 36B = 38 A
40B = 38C
So given a band size of 38, your wife has gone from an A to a C cup, which, again, is about double the original amount of breast.
I hope this helps!
Your wife needs to double check her size on r/ABraThatFits, because most women are wearing very much the wrong size.
40B is for a 40” underbust, and 42” bust. Thats very small. The Irish Bra Lady on instagram has great examples of what properly fitted bras look like. Trust the size calculator on r/ABraThatFits, it’s such a game changer for comfort and fit!
Letters don’t represent equivalent cup volumes.
The cup volume for a 34C is the same as the cup volume for a 36B (sister size).The cup volume for a 40B is much larger than the cup volume for a 36B because the cup volume is larger for a B cup with a 40 inch band compared to a 36 inch band.
34C= 480 cc
40B= 710 cc
40B IS bigger than 34C. You don’t understand how bra sizing works.
I guess a shorter way for me to say it is Bra sizing makes zero sense unless you’ve lived through it. I was a 32B at 4’7″, and now I wear a 40C. …and yes, my boobs are definitely bigger, even if the letter doesn’t shout it. The cup letter (A, B, C…) only tells you how far your boobs stick out from your ribcage, not how much actual breast volume you have. A 34C projects 3″ from the chest, while a 40B only projects 2″, but the 40B wraps a much wider torso—so there’s more width, more volume, more boob. In real terms, a 40B holds around 800cc, while a 34C is more like 600cc. So yes, when you look at your wife and think her “smaller” size somehow looks fuller, you are not imagining it. You’re just seeing what the sizing charts don’t explain well.
I’m so confused by your question.
The cup size corresponds to the band size, they aren’t equal. So a B cup for a 40 is going to be a lot bigger than a C cup for a 34.
It isn’t just like, you pick your cup size and you pick your band size and put them together.
Each band size has it’s own corresponding range of cup sizes.
I must say that when I saw bras being burned back in the 60s that we would have done away with them by now. I’ve never heard a woman say how much they enjoyed wearing one…
A 40B is equivalent in volume to a 34DD. The cup size is based on the difference between the bust size and the underbust size. The letter represents the ration of bust to underbust (i.e. 34C = 28″-30″ underbust : 34″-37″ bust and 40D = 35″-38″ underbust : 40″-42″ bust) So because her underbust increased, the number went up. Because her breasts did not increase as much, the letter did not stay the same. So her underbust measurement increased by 7-10 inches, but her bust measurement only increased by 6-8 inches.
The older you get… swing low sweet chariots…
Don’t confuse size with shape. Different bras have different shaped cups. 36C breasts are 36+3=39, now a 38B so 38+2=40. So technically you are bigger, but the shape of your breast can change (projection, width), so your breast was 3 inches over band, and now they are 2 inches over band.
It’s confusing for us women as well tbh but like the band size…that’s what mainly changes when you gain or lose weight. Your wife gained quite a bit of weight it sounds like if she now wears a 40 bra compared to a 34. Because the band size is if you took a tape measure and measured her whole chest around your body. So yes her boobs probably seem bigger if any of the extra weight went there but cup sizes kinda depend on the bra. Like I can fit into 2 different cup sizes depending on the type of bra. With any bra really there just might be more or less total coverage and snugness.
The letter (cup size) is always relative to the number (band size); it’s not an absolute size.
The cup size is relative to her chest/back circumference size. At 34 C, she had a bigger cup relative to her chest size. Now at 40B, the cup and her chest are bigger, but in terms of ratio, her chest grew bigger than her boobs. So her boobs grew bigger but the ratio of boob to chest is smaller than before
I also noticed this about your wife. I’m glad we got an answer.
Is she in perimenopause? Breast size can fluctuate when your estrogen goes wonky.
I’m a 34D but in strapless bras I’m a 32DD. Bra sizes are not even equivalent from brand to brand and cut to cut. Full coverage vs a demi cup vs strapless. There’s so many variations.