How to Know If a Bra Fits

Woman wearing white bamboo underware

By: Heather Bien

When it comes to bras, there’s no one-size-fits-all. All breasts come in different sizes and shapes—and that can fluctuate over time. For the best support and comfort, you’ll need a bra that forms to your body. With simplified and versatile sizing, our sustainable bras are equal parts beauty and function. You can feel confident hitting the gym, office, or living room with Boody Eco Wear bras.

Smiling young woman in black bamboo underware

Unsure what that optimal size feels like? We can help you find out. In our brief guide, we’ll take you through some simple tips on how to know if a bra fits and why the perfect fit matters. 

Is Knowing Your Bra Size Important?

In one word? Yes.

Women's bras are more than just decorative pieces of clothing. A good fitting bra provides vital support and cushioning, oftentimes easing pain for women. A properly-sized bra can help with:1

  • Breast sagging 
  • Back and shoulder pain
  • Poor posture
  • Sensitive tissue protection
  • Athletic movements & support
  • Clothes fitting
Light grey bamboo bra

Remember—these benefits apply to well-fitted bras. When you're wearing the wrong size, it can actually exacerbate the effects of wearing no bra. 

Unfortunately, while bra size labels are standardized across stores, the actual measurements are not. One shop’s 34B could feel loose, while another store’s 36C might dig into your shoulders. However, there are a few signs for how to tell if a bra fits.

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What Are Signs You’re Wearing the Wrong Bra Size?

If you think you have the right bra size, you might want to recheck. While old stats—such as 80% of women wearing the wrong bra size—have been debunked,2 plenty of women still choose an ill-fitting bra

Not sure if your bra is the right size? Whether too big or too small, let’s explore the telltale signs of improper bra sizing.

A Bra That’s Too Big

While less common, oversized bras are still an issue. Here are some ways for how to tell if a bra is too big:3

  • Cup wrinkling – Over-sized bras leave extra space between your breasts and the cup, creating wrinkles in the fabric overtime. This effect is prominent in bralettes or non-molded bras (a.k.a., no padding or shells).
  • Body pain – Bras take a (literal) weight off your back. But when loose, that supportive structure is gone. If your shoulders and back are sore after wearing a bra all day, it’s likely your straps or entire bra is too big.
  • Arm-raise test – Adjust your bra to the tightest hook, and raise your arms overhead. If your bra rides up as well, you likely need a smaller band size. 
  • Cup gaps – There should be no gaps or space between the breasts and bra cups. If your breasts don’t fill out the cup, you need to size down. 

A Bra That’s Too Small

The tighter the bra, the more support? Not exactly. Tight bras can actually heighten pain and create a whole new set of problems. Not sure how to know if your bra is too small? Here are some clues:4

  • Skin marks – Chafing, indents, redness, and rashes all point to a tight bra. Most wearers will often find these marks along the band, underwire, and underarm areas.
  • Gore gaps – The gore is that little band section that sits between the bra cups in front. It should rest easy on your skin. Gapping between the gore and your body indicates a tight bra.
  • Spilling breasts – If your breasts are spilling over, under, or to the sides of your bra, then the fit is too snug. Bra cups should be full, but not overflowing or stuffed.
Young woman lying in bed in bamboo underware

How Do I Know My Bra Size is Right?

You know the signs for wrong bra sizes. But what about the right size?

Of course, comfort should lead the way with choosing a bra size. But to make shopping easier, consider these sizing tips inside the fitting room:5

  • Get your measurements – Not all 36D bras are alike. That’s why when bra shopping, coming to a store with your exact measurements (your band and breast circumferences) is more useful than naming a size label. Ask for a professional measurement or size yourself at home. And remember—it can be helpful to remeasure every six to twelve months. For information on how to measure your bra size, reach out today!
  • Consider breast shape – It’s not just the inches that matter. Breasts come in seven shape categories, from round to teardrop to narrow.6 Certain bra types and bra styles accommodate each breast shape best.
  • Wear it correctly – To truly test the bra fit, don’t just throw it on. Lean forward at the hips, hold the cups to your breasts, and then hook the outermost claps. That way, you won’t set up an inaccurate bra fitting
  • Check fit signs – With a well-fitted bra, your breasts should sit evenly between your shoulders and elbows. The front and back bands should also stay at an equal height. And for tightness, one to two fingers should easily sneak under the band.
  • Finger Test – One simple test? See how many fingers can easily slip between your back and the bra’s band. About two fingers (or a half-inch gap) is ideal. 

Easy Bra Fits with Boody

The bottom line? The right bra and correct size will feel comfortable, supportive, and quality. And while that can look different for everyone, Boody makes sure all of our bras meet those standards. 

Need assistance with how to pack bras or wondering if you should wear a bra to bed? We have the answers you need!

About the Author:

Heather Bien is a copywriter and writer based in Washington, DC. She works with retail, ecommerce, and creative brands on their website copy and digital presence, and her freelance writing has appeared on MyDomaine, Apartment Therapy, The Everygirl, and more. When she's not with laptop and coffee in hand, you'll find her planning her next weekend getaway, working on her budding green thumb, or scouting for her next great vintage find.


  1. Willingham, J. Why You Should Be Thanking Your Bra.
  2. Perling, A., et al. Are 8 Out of 10 Women Really Wearing the Wrong Bra Size?
  3. London, B. The 6 warning signs your bra is the wrong size and damaging your breasts.
  4. Torgerson, R. All the Expert Bra Fit Tips and Tricks That You Should Know, Like, Yesterday.
  5. Real Simple. How to Measure Your Bra Size at Home.
  6. Marhol, A. Breast Shapes and Sizes: Everything You Need to Know.

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