#bra sizing

Options are US cup sizes– we're well aware there are multiple measurement systems around the world, but this is probably the most widely known on tumblr.

Despite how much band size affects relative cup size, this is only asking about cup size.

"Ideal" could mean on yourself, on others, or in theory alone.

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You're probably wearing the wrong size. Most people are.

This is a screenshot of the bra company Pepper's size guide. Let's take a look at this, shall we?

Hmm, a 25-26" underbust and a 29-30" bust... sized as a 30A.

No. This is not how bra-sizing works. The band ought to match or be fairly close to the underbust measurement. It HAS to be, to provide any support and to be comfortable. Because, yes, bras can be quite comfortable! In the correct size. A band that is too big is going to ride up and shift and rub and move and be awful. A cup that is too small is going to squeeze your tissue into the band, making it feel tighter, and painful, because now your band is pressed into breast tissue.

Bra sizes are a ratio. The letter by itself is meaningless. There is no such thing as "an A cup" or "a D cup." Both A and D cups look vastly different on different bands. "Size DD+" as a bra size category is similar to a shoe store with a "size 6+" category, except worse, because shoe size really is generally only determined by one number. "DD+" being all the information you're going on to determine a bra size would be like answering the question, "How far away is that?" with, "Five." Minutes? Hours? Miles? Blocks? There's a whole range of things that could mean!

The letters correspond (roughly--people don't come in 2-inch increments) to inches of difference between the under and over bust measurement. So going back to our supposed "30A" up there... let's assume a 26" underbust and a 30" bust. 30 is 4 more inches than 26.

A: 1 inch, B: 2 inches, C: 3 inches, D: 4 inches.

Yes, that's correct. That person Pepper is trying to shove into a 30A should be wearing a 26D. A 30A bra would be for someone with a rough underbust measurement of 30 inches and a rough bust measurement of 31 inches. 1 inch difference. Whereas the 26D is for 26 under, 30 over. Notice how the 26D is actually a SMALLER total circumference than the 30A? Cup size scales with band size.

The reason this company pisses me off in particular is because if they wanted to be a niche "smaller boobs" bra company, there is a HUGE untapped market in people who need sub-32 bands. A few carry 30s and 28s but good luck if you need a 26 or 24. And they could help more people get into PROPERLY fitted bras, instead of tossing them into matrix sizes and pretending they're special.

I saw this on their website: "The industry designs for 36C. We design for AA, A, and B."

YOU CANNOT DESIGN FOR CUP SIZE INDEPENDENT OF BAND SIZE.

Also, the industry designs for fucking no one. The industry calls "A cups" small and "D cups" large, tosses out 32-40 in bands and A-DD in cup sizes and calls it good.

DD is five inches of difference between under bust and bust. 5 inches on a person with a 30-inch underbust is going to look MUCH different than 5 inches on a person with a 38-inch underbust. A circle with a total circumference of 43 inches is MUCH larger than a circle with a total circumference of 35 inches.

If you wear bras, and you want to make your life infinitely better, I beg, plead, urge you to go to abrathatfits.org and do the calculator. (Particularly if you've always been sized as an A or B cup, because those are actually very rare true sizes on any band.) The calculator actually takes into account 6 measurements, because for some people a leaning bust measurement is more important than a standing one. Believe the calculator. It will almost certainly give you a band size smaller than you expect and a cup size much larger than you expect. It's not perfect, so it's a good idea to try a cup larger and smaller, too, but it's generally very close. Try different sizes in the same bra--and NOT a t-shirt bra or any bra with molded/formed cups. almost no one properly fits those. Look for an unlined, seamed bra. Go by UK sizing, and stick to the UK brands. (Bare Necessities carries a bunch of them.) US bras are horribly inconsistent, especially in larger cup sizes. UK brands also generally have a far larger size range.

Any time you try on a bra, be sure to "scoop and swoop" to ensure ALL of the breast tissue fits into the cup. A big issue with ill-fitting bras is breast tissue that migrated to the armpit. You ever notice a little bulge on the side at the top of the band under your arm? There's a good chance that's actually displaced breast tissue.

Also check out The Irish Bra Lady on Instagram. She has tons of posts showing what properly fitted bras look like, in a wide range of sizes. If you're really in doubt about the size the calculator gives you, check her account first, she probably has a picture of someone in that size or close. It's helpful sometimes to see what it actually looks like.

Unfortunately, size is only one aspect of a well-fitting bra. Shape is equally important. Some bras have taller cups, some have shorter, which work better for different root sizes. There's fullness, is it mostly on the top or bottom? Even? Horizontally? Close set, wide set? Projected, shallow?

Go through all the resources at the abrathatfits subreddit. They have tons and tons of information to help determine your shape, what bras might work best for you, and the commenters are incredibly helpful if you need to make a post to ask a question.

I'm not going to lie, it took me probably 6-9 months to find a bra that fits? I have to buy mine from Poland. It was a bit of an ordeal.

But now? Now, I think about my bra exactly twice per day: once when I put it on in the morning and once when I take it off in the evening. I don't notice it. It doesn't shift. It doesn't poke. My straps aren't cutting into my shoulders or falling off them. I'm not constantly "reseating" my boobs. It turns out they stay put just fine if you give them a seat they actually fit into.

Finding a well-fitting bra is up there with medication and regular exercise in terms of its contribution to my quality of life. It's confusing, and there's a LOT, but it is SO fucking worth it.

You know that TIkTok trend question that's all, "if you HAD to start talking about one topic for 30+ minutes straight, what would you talk about?"

Yeah.

I'm so confused by this recommended size? Like, right now I'm wearing a 40B and the cups are a little large.

The 1st time I got measured I was a skinty lil middle schooler & the lady that measured me told me I was a 36C. Lol my mom & I were surprised ofc bt hey she was the professional. I've worn that size ever since bc it felt comfortable 🤦🏽‍♀️ (as comfortable as clothes can be). But here's the thing, my adult underbust/band is 30" & as I mentioned I was a skinny kid, where tf did she get 36" from 🤔 & then to have a 3" difference to get the cup size. That just means I have literally never worn the correct bra size ever 🤣 Who knows if I ever will bc all I ever hear from big tiddy committee is: can't find, too expensive, uncomfortable, not cute. Ugh I was fine with being mid tiddy committee 🙃

*Also fun story: myself & 2 of my friends pulled a sisterhood of the travelling pants & swapped bras at a party bc... science I guess 🤷🏽‍♀️ lol. We all fit each others bras which made no sense then & now makes even less sense... other than damn near all boob owners are not wearing the right size 😫

Not necessarily, in my experience. Though we do have a post detailing how to measure your band and or cup size in the bra sizing tag at the end of this post! (I tried using that method and turns out I was wayyyy off with my bra size).

Unfortunately sometimes the elastic on bra straps is Not Good and they can easily be worn out. It may just be time for a new bra, but of course do check to make sure your bra size is correct as well!