How Should a Bra Fit Correctly?

blond woman wearing pink lace bra
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Are you uncomfortable or unable to move well whenever you wear a bra? 

The most likely reason behind this is that you’re wearing a bra with the wrong fit. But how should a bra fit correctly?

Below, we’ve created a bra fit guide to help you find more comfort and better support in your bras.

Remember, you wear a bra to cover, support, and elevate your breasts. 

Its job is to make you look and feel good, no matter your breast size. 

It should not be a hassle that you need to go through every day.

Steps on How to Know If Your Bra Is Too Small

Let’s tackle the issue of wearing a bra that’s too small first. 

One of the signs you’re wearing a tight bra is chafing.

Does your skin have irritation, heat rash, folliculitis, dermatitis, or even hives at the band area? 

Your bra is too small if you feel the band, straps, or underwire digging into your skin uncomfortably.

Do you have benign skin lesions like moles that fall on the bra area? 

A tight-fitting bra can rub on these skin lesions and cause them to swell or bleed. 

If you live in warm climates, sweat a lot, or swim with these lesions opened, you may even get infections from them.

You may also feel back and shoulder pain, which is the cause of having a small cup and loose band. 

This kind of bra fit is unsupportive and harmful to your spine health. 

You’ll most likely tighten the straps on your bra if the band is too loose, which strains your shoulders.

A tight bra may press on your abdomen and cause acid reflux. 

Acid reflux is when you regurgitate what you ate or drank, and it can cause various complications. 

A tight bra can worsen it if you already experience acid reflux often.

A less drastic effect of wearing a small bra is spillage. 

It is when your breasts slip out of the cups sideward or to the front. It’s a sign that you’re wearing bras with cups smaller than your size.

How to Tell If Bra Cup Is Too Big

What if a small or tight bra isn’t the problem but the opposite? 

Here are the signs you’re wearing bras that are too large or loose for you.

The gap between your breast and the bra cup is the easiest way to know you need to get a smaller bra size. 

Do your boobs fill the cup, or is there a lot of room left for hiding bills, tissue paper, or knickknacks in there? 

You have the wrong bra size if you notice space between the cup and breasts when you stand, sit, or bend over.

You may also notice your bra cups becoming wrinkly, even when you’re wearing the bra. 

It means the cups are too large for your breasts. 

The cups will bunch up, wrinkle, and create a “double boob” since they won’t have anywhere else to go. 

It’ll look unsightly and may cause wardrobe malfunction at the worst of times.

A common reaction of many women is to tighten their bra straps. 

It’s why some people experience having their bra straps slide off their shoulders.

Being uncomfortable isn’t the only impact of wearing a bra too large for you. 

When your straps become too tight, but the bands remain loose, the band will ride up on your back.

When your straps pull the band up to your back, they also carry all the weight. 

It’ll leave strap marks and lingering soreness on your shoulders.

How Your Bra Should Fit

Look through your bra collection and notice how each one and its components fit you. 

Some bras may have loose straps but the correct band size depending on the type. 

Others may feature the wrong cup size.

Check how your bra fits by knowing how each component fits best on your body. 

Here are how the following parts should fit you.


The cups must form to the curve of your breasts. 

The tops of the cups should meet your body. 

A well-fitting cup shouldn’t cause any gaping or bra spillage.


The straps must sit snugly on your shoulders to offer optimal support. 

They should not leave marks or slide off your shoulders.


It should provide most of the support. 

A brand new bra should have a band that fits snugly at the loosest hook. 

Over time, the band will stretch, which is when you’ll switch to the next hooks. 

It also shouldn’t constrict or dig into your skin.

How to Find a Bra Size that Perfectly Suits You

How do you check that your bra is the correct size the next time you shop for one?

The first step is to know your band size and cup size

You can get your band size by wrapping a tape measure around your back and under your breasts. 

Notice this is where the band usually goes. Next, round the bust measurement to the nearest whole number.

Next, find your cup size by measuring your bust. 

Again, bring the measuring tape around your back then over your nipples. 

You need to perform some quick math to get your cup size. 

Subtract the difference between the band and bust measurements.

The corresponding cup size to the difference is:

  • 1 inch = A
  • 2 inches = B
  • 3 inches = C
  • 4 inches = D, and so on

Let’s say your rib cage measurement is 33 inches and bust size is 36 inches. 

The difference between the two is three inches, which means you get a C-cup. 

For this example, your bra size is 36C.

Many women have breasts of varying sizes, but these differences are often relatively small. 

If you have asymmetrical breasts with significantly different sizes, pick a bra size that fits the larger breast. 

To wear it, add a bra cutlet or pad in the cup for the smaller breast.

Finally, remember that not all women have the same type of breasts. 

Some have wide-set breasts, while others have teardrop-shaped breasts

Find your breast type to pick the right bra type.

Pro Tip: Know Your Sister Size

Not all stores or brands will have your bra size. 

A great way to get around this limitation is to find your “sister size.” 

A sister size is an alternate size with the same cup volume. 

Your band size and cup letter may change in your sister size.

The process of finding your sister size is easy. 

If the band measurement increases, the cup size must decrease and vice versa. 

Let’s go back to the 36C bra size example. 

Its sister sizes are 38B, 34D, or 32DD.

Don’t overlook the benefits of knowing your sister size. 

Your sister size may even fit you better than your true size. 

Experiment with your sister sizes. 

You may find a more suitable bra size in them than in the traditional bra sizing method.