Believe it or not, boobs are a complex part of life that many women do not fully understand. That extends to bra measurement and finding the perfect bra size.

It’s not as simple as just having boobs and living your life – you have to take the time to learn your exact bra size, you have to worry about cheap bras damaging your breasts, you’re usually provided with a very limited selection of bras if you’re busty, not to mention all the aches and pains that accompany large breasts.

Luckily I’ve created this ultimate guide that is sure to give you a lot of insight! Hopefully boobs will make more sense after today.

First, let’s talk about how to measure your breasts

Gather your materials!

In order to calculate your bra size, you’ll need a soft measuring tape. A long string or piece of fabric could work, too, if you are planning on measuring it later with another object; understand that your sizing might not be completely accurate if you don’t actually use a soft measuring tape, though.

If you are very forgetful, it might be necessary to gather a pen and paper, too, unless it’s easier to get the keyboard on your smartphone ready.

Get naked

You don’t have to get completely naked (duh?), but make sure you are completely bare from the waist up. No sports bra, nothing.

Measure your band

Band size refers to the number in bra sizes. For example, if you wear a 32DD, your band size is 32 inches.

These steps will help you find your band size:

Wrap the measuring tape around your upper torso

This part might sound funny, but you want to wrap the soft measuring tape around your torso so that it sits at the roots of your breasts.

Here is an example highlighting roots. 

Basically to put the tape measure where your roots and torso meet, you will put the tape measure as high up on your torso as it can possibly go before your breasts interfere.

If that’s still confusing, put the tape measure under the folds of your breasts instead of lower down on your torso where your breasts are hanging.


Once the tape measure is sitting at the roots of your breasts, exhale and let all your air out.

The tape measure should feel snug – it should not be loose, but it also should not dig into your body. Bras stretch, so it’s important that you remember to exhale to get the proper band size.

If your band is larger than 36 inches, you’ll want to pull the tape as tight as you possibly can without causing discomfort.

Record your answer

Write your band measurement in inches on paper.

Measure your cup size

Cup size refers to the letter in your bra size. If you wear a 32D, the D stands for your cup size.

Lean forward

You have to lean forward so that your back and the floor are parallel.

Make sure all of your breast tissue is hanging forward, including migrated breast tissue

Are you wondering what the heck migrated breast tissue is?

The term sounds funny, but you’ve probably had it for awhile without realizing what it was.

Migrated breast tissue is breast tissue that has migrated away from the breasts over time and moved into your underarms or back instead. This tissue usually presents itself as “fat rolls”.

Because migrated breast tissue usually occurs as a result of a bra that is too small, it can often be fixed over time by wearing a bra that supports you properly.

Now that you have a better understanding of migrated breast tissue, you need to massage your sides and your back after you lean forward to make sure all of it comes forward for an accurate measurement.

You want to kind of push your tissue forward in a sweeping motion.

Wrap the measuring tape around your bust

You want the measuring tape to fit loosely around your bust. It should be placed over the fullest part of your breasts, which is near the nipples and areolas for most women.

Instead of pushing the band down into your cleavage and between your breasts, measure all the way around by putting the measuring tape straight over the gap between your breasts.

The tape should only be tight enough that it would not slip off when you move.

Record your answer

Write your bust measurement in inches.

Pendulous breasts

This section will not apply to even woman, but it will apply to some.

Pendulous breasts are breasts that are neither round or perky. These breasts are long and cylindrical instead of short and circular.

If this is the case, you should measure your bust while bending down as we discussed, but you should also measure your bust a second time while standing.

Add your two bust measurements and divide them by two to get an average; this will be an accurate bust measurement for you.

To find your bust measurement while standing, do exactly what we talked about earlier; put the measuring tape around the fullest part of your breasts and record your answer in inches. The tape should fit loosely around your breasts.

Measuring one breast that is larger than the other

For women who have one breast that is much larger than the other, some people recommend you measure the perimeter of the individual breast that is bigger.

In order to do this, lean forward so that your whole breast is easy to see and reach.

You will need to measure from the furthest point of your sideboob and measure across the furthest part of your breast and over to your cleavage.

The measurement in inches is equivalent to your cup size.

For example, if your breast is six inches across, there’s a good chance that breast is a DDD. This is important since your other breast might be a D or a DD. You’ll probably want to choose a bra according to your larger breast.

This is a common occurrence among women who have had breast implants, but it can certainly happen naturally, too.

Measuring cup size for transgender women

Bra fitting for transgender women is slightly different than it is for other women.

You can measure your band size the same way I already mentioned, but the cup size is found differently. Since transgender women typically have a V-shaped rib cage, overestimating the cup size is easy to do!

Lie down

You’ll actually need to lie flat on your back.

Wrap the measuring tape around the fullest part of your breasts

Wrap the measuring tape around your breasts the same way you would if you were standing.

Do not worry about trying to push or lift your breasts while measuring your bust! Measure them according to how they naturally rest on your body.

Instead of pushing the measuring tape down between your breasts, measure across them, like a bridge going from breast to breast.

Record your answer

Write your measurement in inches.

Calculating your bra size

Finally, we get to the fun part! There are bra sizing calculators all over the internet, but because they are often inaccurate, I advise you to bypass those tools and calculate your bra size using Old Faithful. (Your noggin!)

Confirm your band size

If you didn’t round already, your band measurement needs to be rounded to the nearest whole number.  For example, a measurement of 34.5 would be rounded up to 35.

If your measurement ends up being an odd number, you’ll need to round to the nearest even number. For example, that 35 inch bust needs to be recorded as a 36 inch bust.

Conversions for international band sizes

          US           UK               EU      Australia

          28”               28”               60 cm               6

          30”               30”               65 cm               8

          32”               32”               70 cm               10

          34”                34”              75 cm              12

          36”               36”               80 cm              14

          38”               38”               85 cm               16

          40”               40”               90 cm               18

          42”                42”              95 cm               20

          44”               44”               100 cm             22

          46”               46”               105 cm             24

          48”               48”              110 cm              26

          50”               50”              115 cm              28

Notice I did not put anything after the Australian sizes like “inches” or “centimeters”.

The sizes listed for Australia are considered your “body size”. Each number correlates with how many centimeters around you are.

For example, if you are 75 centimeters around, you are considered a size 12 in Australia rather than just 75 centimeters. It’s kind of similar to buying jeans that come in sizes 0, 2, 4, 6, 8, and so on – each size is chosen based on how many inches wide the pants are.

Confirm your cup size

Round your bust measurement up to the nearest whole number.

It does not matter if this measurement is an odd or an even number.

Subtract your band measurement from your bust measurement; the difference between the two will determine the letter than corresponds with your cup size.

For example, let’s use that 36 inch band as a reference. Let’s also say your bust measurement is 42 inches. Subtract 36 from 42 and notice the difference is 6 inches. A 6 inch difference makes your cup size a DDD or F (they’re the same thing).

Once you calculate the difference between your measurements, use these numbers as a reference:

Conversions for international cup sizes:

          US           UK               EU      Australia

0”          AA               AA               A                AA

1”           A                A                 B                 A

2”          B                 B                 C                B

3”          C                 C                 D               C

4”          D                 D                 E               D

5”          DD/E           DD              F               DD

6”          DDD/F         E                G               E

7”          DDDD/G      F                H                F

8”          H                  FF              I                FF

9”          I                    G                J              G

10”        J                   GG             K              GG

Bra sizes by company

It’s very important to do research on a company before purchasing a bra from them.

Some companies sell bras that are smaller in the band than bras from most other companies, and other companies have cups that are smaller, too big, and so on.

Ewa Michalak, Ultimo, and Panache are known to have bands that run small, so you’ll want to order one band size larger from them.

Bras by Freya and Change Lingerie have bands that are bigger than usual, so it might be necessary to purchase a band that is one size down.

The same differences can be true for cup sizes, too. Check into each company’s reviews and make sure to read their sizing charts carefully.

Any time you have to go up or down a size on your band or cups, it’s important that you understand how sister sizes work and try to find a sister size that will meet your needs.

Sister sizes

Sister sizes refer to bra sizes that are very similar or even equivalent to one another in terms of cup volume. You should always try to wear a bra in your exact size, but sister sizes can be used as a substitute if it is absolutely necessary.

Usually women do not WANT to pick a sister size. The way many women end up purchasing one is because they’re often tricked by sales associates at mass retailers into purchasing a size they do not belong in. (I will elaborate more on that topic shortly.)

As you’ll be able to infer by the conversion charts I’m about to show you, sister sizes make sense when they’re one size away from each other.

However, the further away you get from your actual size, the more ridiculous the concept becomes.

US sister sizes

28D = 30C = 32B = 34A = 36AA

28DD/E = 30D = 32C = 34B = 36A = 38AA

28DDD/F = 30 DD/E = 32D = 34C = 36B = 38A = 40AA

Hopefully you get the idea. Sister sizes work the same way with international sizes.

In case you’re unsure, you cannot fit your 30DD breasts into a 40AA bra. It does not matter how big the band is – DDs are not going in a AA and I don’t care who tells you otherwise! Your breasts will not be covered and the band will slide back and forth around your torso.

Some women also go up on their cup sizes.

For example, 38C = 36D = 34DD/E = 32DDD/F = 30G

Again, sister sizes can temporarily work if you’re going from like a 32D to a 30DD/E, but it’s not a permanent fix and any change more drastic than that is not going to work.

This goes back to what I originally said about companies running big or small; it’s important that you know your sister size in that situation.

So why are most women wearing a sister size?

Women who understand bra sizes do not typically opt to wear a sister size because they know that they just don’t work the way people claim.

Most women who are wearing a sister size are doing so unknowingly because they have been tricked by employees at stores like Victoria’s Secret about their real size.

When you enter a store that has limited sizes like Victoria’s Secret, the associates are trained to fit you into a bra that’s available in their store.

If you enter their store thinking you wear a 34DDD, and the associate knows they have a limited stock in that size, they’re likely to fit you into a 36DD and try to convince you that that’s your size.

Then they’ve made a sale and you’re left with a bra that does not fit properly.

Even if a store has your size online, the associates know that you’re more likely to leave the store and take your business elsewhere before you’ll take the time to shop online for a selection of bras that’s already very limited. This is how hundreds of women end up in sister sizes without realizing it.

Band size

Band size is extremely important. Your band is one of the main parts of a bra that supports your breasts, so it is completely necessary to make sure you are fitted correctly.

If your band size is too loose, your breasts are likely to fall through the bottoms of your cups.

If your band is too tight, it’s likely to restrict your breathing and force your breasts to overflow in every single direction – especially into your armpits.

I came across this article that I think most women AND men will find very eye opening. 

It discusses the common misconception that a woman’s cup size determines everything about her breasts – that if you have a D cup, your boobs are huge, and that it doesn’t matter if you wear a 40D or a 34D, either way the boobs are the same size. I can assure you that is not the truth.

Cup size

As the above article mentions, the cup size only tells us how far our breasts stick off of our chests.

That means that a woman in a 30DD and a woman in a 42DD both stick out five inches further than the trunks of their bodies, but those pair of breasts are NOT the same size simply because they each require a DD cup.

That same article said this, corresponding with what I just mentioned in the above paragraph:

“They are not the same size, they are just the same relative size – by that I mean the ‘DD’ is an indication of how proportionally large the bust is in comparison to the frame, NOT how large the bust is all on its own.”

How to put on a bra

I know you are thinking I must think you’re stupid if I think you don’t know how to put on a bra. I can guarantee that I in no way think that’s the case!

But honestly, has anyone ever sat you down and said “Okay, first, you do this…”?

I doubt it!

Putting on a bra is something that women are just expected to know how to do. It’s something that should come natural to us since after all, they’re our own boobs.

But if you got a group of women together and asked them all how they put on a bra, I can almost promise the answers would vary. While you’re probably thinking “Who cares? It’s not rocket science!” I can assure you there ARE right and wrong ways to go about putting on a bra!

Follow these steps:

Put your arms through the straps

For a traditional bra with normal straps and a back closure, the first thing you need to do is put your arms through the straps.

Hook it closed

Then you need to hook the bra so the closure is closed. Most bras three or more tightness “settings”. A new bra should fit on the loosest hook, giving you the option to tighten the bra over time as the band stretches.

If you have trouble reaching behind your body, you can bypass the first step – then, put your bra on backwards, clasp it in the front, and then turn it back around and put your arms through the straps.

If you put your bra on backwards, you must be careful for two reasons:

First, you can damage the elastic in the band if you do not move it gently enough.

Also, you can irritate your upper torso or the folds under your breasts by rotating the clasped bra around your body. The elastic and the fabric covering your bra are likely to cause discomfort as they rub against your skin. Just be careful not to pull the bra around too quickly.

Next, adjust your straps

Make them tighter or more loose depending on your needs.

Make sure the straps are not falling off or digging into your shoulders; they should feel snug and comfortable.

Check sure everything is fitting comfortably

Gently tug on the straps and the band of your bra to make sure nothing is digging into you or falling off.

You should be able to fit one to two fingers between your body and the band of the bra, but nothing more or less than that.

Make sure that the band, the straps, and the center gore of your bra are not twisted.

Everything should be in its proper place.

Now you’ve got to make sure your breasts are where they should be in the cups

Bend your upper body forward so that your breasts kind of lean off of your body.

Use your left hand to position your right breast and your right hand to position your left breast in the cups.

You’ll want to lift each breast inside of their cups so they’re not squished down. Make sure there’s no breast tissue falling over the sides of your cups; if there is, your bra is either too small or your breasts need to be positioned a little closer together.

When I tell you to lift your breasts, I’m telling you to lean forward and do the “scoop and swoop”. This simply means that you literally bend forward and use your hands to scoop the sides, bottoms, and tops of your breasts into the cups so they’re completely concealed and as perky as possible.

Stand up straight when your breasts are completely supported

You need to make sure the underwire is actually touching the part of your body underneath your breasts to avoid them spilling out when you move around.

Your breasts should look perky rather than droopy or compressed.

Check the fit

Is it comfortable?

If it’s not, that’s the biggest indicator that the bra does not fit properly.

Of course there are other factors that contribute to the overall comfort of the bra, like whether or not the fabric is itchy. Itchiness does not determine the fit, but surely you wouldn’t wear an itchy bra anyway.

When I ask you if your bra is comfortable, I’m asking you if your rib cage is being squeezed, if your shoulders are being dug into, and so on.

These are specific factors to take into consideration before you can determine whether or not a bra is comfortable:

Common fit problems

Loose straps

If your straps are falling off your shoulders, they’re too loose.

When your straps are too loose, they allow your breasts to sag, your cups to slide down, and your breasts to move around freely.

Tight straps

Tight straps are no better than loose straps.

When your straps are too tight, they dig into your shoulders, causing your shoulders and your neck to ache.

Not only that, but they can pull your breasts up and towards your chest, making them feel like they’re being strangled and causing them to ache, too.

Straps that are too tight will give you shoulder grooves, or indentations on the tops of your shoulders that are sensitive and sometimes permanent.

Tight straps are also likely to make you slouch forward, making you have poor, unattractive posture.

What’s the solution?

Adjustable straps

If you wear a bra with non-adjustable straps, you are asking for trouble. The straps might feel comfortable initially, but the more you move around, the more likely you are to find they’re either too loose or too tight.

This problem can be eliminated if you simply make sure the straps are adjustable!

Comfort straps

Your comfort straps should be both padded and wide.


The padding on comfort straps will keep you from suffering from shoulder grooves. Even if your straps are a little tight, the padding should keep the sides of the straps from digging into your shoulders and making you suffer through unnecessary discomfort.

Wide straps

As far as the straps being wide, that’s a factor that’s just as important as the padding.

Wide straps can hold more weight that thin straps. As you can imagine, that’s essential for women in the busty community.

The more your breasts weigh, the more they pull down on your straps. If your straps aren’t wide enough to support you, that’s when painful things like shoulder grooves happen,

With that being said, if you wear a bra that has both padded AND wide straps, your shoulders will be thanking you later.

Band is too tight

If the band is too tight on the loosest hook, you need to go up a band size.

If you are unsure if your band is too tight, evaluate the way it fits:

Is it squeezing you to the point that it hurts to breathe?

Is it so tight on your rib cage or your back that it’s painful to lie down?

Do you have bulges protruding and showing through your blouses around your shoulder blades, mid to upper back, or armpits?

If so, there’s a good chance your band is too tight.

Band is too loose

If your band still moves around on the tightest hook, it’s too big for you and your breasts will not be supported properly.

You should be able to pull the band one to two inches away from your body, but please note that any more or any less space than that means the bra does not fit.

What’s the solution?

You need an adjustable closure

Similar to the straps, only purchase a bra that has an adjustable closure.

Bras with a band that you pull over your head and shoulders are no good.

You must be able to adjust the clasps. If your band is comfortable on the loosest hook, that’s a good indicator that it fits you well. This is because bras stretch out over time, so you might eventually need to move to the middle or tightest closure.

Look for a wide band

This is not a necessity, but it certainly contributes to your overall comfort.

If your bra’s band is wide underneath your arms and across your back, it will conceal your flesh or bulges much better than a band that is thin.

This will ultimately make you feel better, not only because you’ll know you don’t have bulges, but because there will not be a pesky band digging into your underarms and back.

If bulges are a concern for you, opt for a bra that gives your back full coverage. These high-backed bras will extend from your middle to upper back or neck, proving you with maximum coverage against frustrating back fat.

The center gore or bridge of your bra does not touch your chest

The center gore, or bridge, of your bra is the front middle piece that connects the cups.

If this piece is not resting comfortably on your chest, your bra is too small!

What’s the solution?

If the center gore is not resting against your body, that’s an indicator that your cups are too small. You’ll need to go up at least one cup size.

Your cups are too small

When your cups are too small, it causes a world of problems. Your boobs get achy, they sweat, develop rashes, and so on.

But how do you know if they’re too small?

You’ve got a quadraboob

Whaaaat did I just say?!

A quadraboob occurs when your breasts overflow the tops of your cups, creating bulges that extend over the cups and giving the illusion that you’re hauling four breasts around.

Cleavage is one thing, but when the tops of your breasts are actually poking further out than your cups, that’s a problem.

Your boobs are spilling out of the bottom of your cups

If the tops of your breasts are covered, but they’re coming out of the bottom of your cups, the bra is too small.

Your cups should be able to completely hold your whole entire breasts. Even if you’re wearing demi cups, your breasts should never overflow.

You have embarrassing “armpit fat”

Armpit fat is often a result of cups that are too small. It’s usually not the armpit itself that is extending over the outside of the cups, but breast tissue that does not fit where it should.

Your cups are too big

If you have extra room in your cups, they’re too big.

Your breasts should not be swallowed by your cups and there should not be a gap between the cups and your breasts!

What can I do about ill-fitting cups?

Wellll, in case it’s not obvious, go up or down a cup size depending on whether they’re too tight or too loose!

When bra cups fit, your breasts should feel comfortable. The bottoms of your breasts should not be exposed and the tops should not overflow. You’ll have cleavage, but no awkward bulges coming out of your cups.

The underwire is stabbing your sides and underneath your breasts

Underwire can be a serious problem when it digs into our skin.

Before I understood what it meant to have a bra that fits appropriately, I had my fair share of uncomfortable underwire mishaps.

I had several bras that were too small for me; more specifically, my cups were too small. This put excess pressure on the cups and eventually made the underwire kind of bust out of the fabric.

This resulted in extreme discomfort and even bloody cuts a few times when I was out in public and could not fit my bra because people were around

The underwire simply could not support the weight of my breasts because the bra was too small to support me.

What is the solution?

First, you probably need to go up a couple sizes.

You also need to check that you’re not wearing a bra that was cheaply made. If the bra is made of poor material, the underwire is likely to poke through whether the bra is too small for you or not.

Do not purchase a bra for $5 at the mall just because it’s a pretty color and it seems like a steal.

You will physically and mentally feel the difference when you are wearing a bra that treats your breasts right.

How to take care of your bras

Invest in more than one to two bras

When you continuously wear the same bra(s) over and over, the elastic wears out too soon, the underwire begins to poke through, and they begin to look dingy overall.

It is not a bad idea at all to have five+ bras. I know bras can be expensive, so if you only have one bra you might not be able to click your heels and purchase four more immediately.

You should at least purchase new bras gradually and build up your collection to give the bras you do have a better chance at survival.

Our bras have a lot of work to do, and when one bra is expected to take care of all of our needs, it becomes extremely run down the same way humans do under stress.

Hand wash your bras

Use lingerie wash if you can. If that’s not an option, that’s okay, use what you have.

Hand wash your bras and let them air dry.

Do not put them in the dryer, do not bleach them, and do not iron them.

Try to wash your them every two to three wears.

What about bralettes?

A bralette is a bra that is completely free of underwire and padding. It is extremely lightweight, allowing your breasts to breathe; it is often worn as a fashion statement rather than an actual bra. These bras are often lacy and available in many colors, so they accent tank tops and blouses well when they are worn under clothes.

Most women with large breasts think that they cannot wear large breasts, and unfortunately that is the case with a lot of companies. However, recently bralettes have come available in a wider range of sizes and women with large breasts can absolutely wear them!

Feel free to look over this post I wrote about the five best bralettes for DD+ cups. 

I would like to talk about sizing with bralettes

Bralettes often come in vague sizes, like XS through XL.

If these are the only kinds of sizes available, you might be able to get by with one, but you should really look for a bralette that comes in specific sizes, like 34D or 36DD.

Do not expect a bralette to lift and support your breasts

If your breasts are naturally saggy, a bralette probably will not help you much in that department. As I said, they have no underwire or padding, so while a bralette will conceal your breasts, it will not lift them by any means.

The saggier your breasts, the more likely they are to look flat in a bralette.

Even if your breasts are not lifted in a bralette, they will still look beautiful in all that lace

The lack of support has not stopped many women from wearing bralettes. They are beautiful, they let our breasts breathe, and they’re easy to take care of.

Make sure you understand your exact bra size so you don’t accidentally tear the lace on a bralette that’s too little!

Finally, we can talk about the last topic. It might seem unimportant, but I promise it matters!

In Summary

There you have it: an ultimate bra measurement guide for DD+ cups! I hope you gained tons of boob knowledge today, and if there’s anything I left out, please let me know in the comments! You can also watch this great video from Curvy Kate (one of my favorite brands) on bra fitting:

If you enjoyed this article, then we're probably very similar. I'm Victoria Melo, and I know what it’s like to be busty and struggle finding the perfect bra. Not long ago, I was just another girl wearing the wrong bra size. When I finally discovered my real size and found great bras for my busty figure, it felt like a miracle. Now, I'm a bra fitter helping hundreds of women like you find their own miracle. Click here to read my lists of my favorite bras for you.
Nice to see you again. Would you like to get expert help to create your own Bustiest plan?YES, PLEASE!

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