How To Measure Your Bra Size

Key Takeaways:

• Fit Matters More Than You Think: Finding the right size bra is essential for comfort, support, and confidence.
• Watch For These Red Flags: Digging straps, gaping cups, or a band that rides up your back are common signs your bra isn’t fitting properly and may need a size reassessment.
• Measure Then Match: Taking accurate measurements and referencing a bra size chart can help guide you to a fit that supports your unique shape.

Figuring out how to measure your bra size is a personal and often frustrating process that comes with a lot more trial-and-error than it should. For too long, we’ve settled for straps that dig, bands that ride up, and cups that never quite sit right. But your comfort and confidence deserve better.

At Saalt, we believe understanding your body is the foundation of self-care. Whether you’re looking for a matching lingerie set or simply trying to find a bra that fits perfectly, knowledge is power — and that includes knowing how to determine your bra size. This article is all about learning to measure your body and choose support that embraces your unique shape. Just like our sustainable, feel-good period care, your bra should make life easier, not more complicated.

If you’re ready to take the guesswork out of bra sizing, you’re in the right spot. Let’s walk through it together, one measurement at a time.

Signs You're Wearing The Wrong Bra Size

How do you know if your current bra is doing its job? Most of us learned to settle, dealing with pokes, pinches, and shifting straps, because we thought “close enough” was “good enough.” But your body deserves the sense of relief that comes with wearing something that fits well. Here are a few signs that your bra might be missing the mark:

1. Digging Straps or Band: If your straps are digging into your shoulders or your band leaves deep marks, it's a sign that the support isn’t balanced. Most of a bra’s support should come from the band, not the straps. A snug-but-comfortable band helps distribute weight evenly and keep everything in place.
2. Overflow Or Gaping: Spilling out of the cups? Not filling them out all the way? Either one points to the wrong cup size. A well-fitted bra should gently hug your breast tissue with no bulging or gaping. Not sure where to start? A bra fitting guide or a bra size chart can help you find a better match.
3. The Back Band Rides Up: If the back of your bra is climbing north by lunchtime, chances are your band is too loose, even on the tightest setting.
4. Underwire Discomfort: Underwire poking or floating off your body is a classic sign of the wrong size or style. When it fits well, the underwire should sit comfortably against your ribcage, surrounding your breast tissue without pressing into it. If wires just aren’t your thing, try a supportive alternative like our breathable mesh bra. According to NIH research on breast discomfort, supportive, non-restrictive garments like bralettes can improve comfort and reduce skin irritation, especially in post-mastectomy women.
5. Constant Re-Adjusting: If you’re adjusting your bra more than your playlist, something’s not right. A good fit should stay in place, feel secure, and let you move with ease, whether you're lounging, lifting, or running errands.
6. Lack of Support or Shape: Support isn’t about lift alone; it’s about how you feel. If your bra leaves you feeling unsupported while moving or doesn’t give you the shape you’re looking for, it might be time to look into different styles that work with your body. Whether you're shopping for bras for small boobs or a bralette with support, there's something made for you.

Your comfort isn’t negotiable; it’s foundational. If you’ve experienced any of these fit frustrations, know that a better bra is out there, and it’s probably a lot more comfortable than you think! At Saalt, we design bralettes and bralette and underwear sets that prioritize feel, function, and fit. We believe everyone deserves to feel at ease in their own skin, and you’re no exception. Next, we’ll get into how bra sizes work and how to measure yourself for the right fit.

How Do Bra Sizes Work? Let’s Start With The Band

Before diving into letters and cup math, it’s important to understand that your band size is the foundation of your entire bra fit. A common misconception is that straps carry the weight, but in reality, most of your support comes from the band!

Step 1: Set The Scene For Success

Before measuring, take a moment to get centered. Wear a non-padded bra or go braless for the most natural read. Stand in front of a mirror with relaxed shoulders and steady posture. Grab a soft measuring tape (like the kind tailors use) if you have one handy, but a string and ruler will work just as well. For the most accurate measurements, remember that you’re not in a rush, so you can take your time and be thorough. This is a moment of self-awareness, not pressure.

Step 2: Measure Under Your Bust

Wrap the tape snugly around your ribcage, just beneath your breast fold. This is where your band will sit. Make sure it’s level all the way around and lies flat against your skin. According to Women’s Health Magazine, this underbust measurement (in inches) is your starting point. If you land on a fraction, round up to the nearest even number. For example, a 32.5" or 33" measurement becomes a 34 band.

Step 3: Know What A Good Fit Feels Like

Your band should feel supportive and secure, not restrictive. When trying on a new bra, start with the loosest hook. You’ll want the option to tighten it as the elastic naturally stretches over time. A well-fitting band stays in place, supports you from the base, and doesn’t leave red marks.

Why Band Size Matters In The Bigger Picture

Understanding how to measure your band size is a key part of learning how bra sizes work overall. Once you’ve locked in the right band, you’re halfway to a more comfortable, body-aligned fit. From there, measuring your bust and calculating cup size (we’ll cover that next) builds on this solid foundation. It’s about showing up for yourself with curiosity, care, and a little extra breathing room.

How To Measure Your Bust Size

Now that you’ve found your band size, it’s time to do the same for your bust. Measuring this area correctly is a small act of self-respect. Your body moves and shifts, and the right fit should move with it. Let’s walk through the steps, keeping it simple and grounded in self-awareness.

Step 1: Measure The Fullest Part Of Your Bust

Stand tall with relaxed shoulders. Wrap a soft measuring tape around the fullest part of your bust (usually at nipple level), making sure it stays level across your back and front. Let the tape rest gently against your skin; no squeezing, pressing, or adjusting needed. This measurement should feel comfortable, not restrictive. Jot down the number in inches.

Step 2: Calculate Your Cup Size

Now, subtract your band size from your bust measurement. The difference between the two gives you your cup size. As a general guide:

• 1 inch = A cup
• 2 inches = B cup
• 3 inches = C cup
• 4 inches = D cup

…and so on. For example, if your band size is 34 and your bust measures 37 inches, your bra size would be 34C.

Step 3: Let The Fit Be Your Guide

Sizing is just a starting point. Let your body lead the conversation. Weight fluctuations, pregnancy, or simply time (gravity makes everything droop a little, and that’s perfectly normal!) can all shift how a bra feels from day to day. So if the size on the tag fits differently than expected, listen to your body, not the label. If the fit feels good and lets you move freely, that’s what really matters.

At Saalt, we believe measuring your bust should feel empowering, not intimidating. Comfort is personal, sizing should be flexible, and you deserve pieces that meet you where you are. When you feel supported, everything else falls into place.

Tips For A Better Fit

If you’re between sizes or feel like your current fit is close but not quite right, sister sizes might be the key. Sister sizing is the idea that you can adjust both your band and cup size — up or down — to find a better match without compromising support. For example, if a 36C feels loose in the band, a 34D might offer a more secure fit while maintaining a similar cup volume. It’s not a perfect science, but it’s a helpful tool when you’re working with subtle differences in fit.

For Uneven Breasts

It’s also worth noting that asymmetrical breasts are more common than you think! Many people have one breast that’s slightly larger or smaller than the other. In general, it’s best to choose a size that fits the larger side more comfortably to avoid digging or pinching. A well-fitting bra should support both sides without gaps, overflow, or awkward adjustments.

Check The Fit Cues

Lastly, pay attention to your body’s signals. A good fit means your band stays level across your back, your cups hug without squeezing, and your straps stay in place without digging into your shoulders. If you’re constantly adjusting, shifting, or noticing red marks, that’s your body asking for a different size.

When To Re-Measure

Bodies change, and that’s natural. Weight shifts, pregnancy, hormone cycles, and time (hello, gravity) can all affect how your bra fits. We recommend re-measuring yourself at least once a year or anytime your body feels different. Staying in tune with your fit helps you stay in tune with yourself.

Need Help? We’ve Got You!

Don't stress if you find you’re between sizes or the size listed feels off. Instead, reach out to our sizing coaches at sayhey@saalt.com for assistance. Whether you’re looking for your best-fitting bralette, period underwear, or the right menstrual cup or disc for your anatomy, we’re here to help you feel confident and supported every step (and cycle) of the way.

Make The Switch

Learning how to measure your bra size isn’t just about getting the numbers right; it’s about getting to know your body with curiosity and care. At Saalt, we believe confidence grows from comfort, knowledge, and the freedom to choose what feels good for you. When your bra supports your natural shape, it’s easier to move through your day with ease, and maybe even a little extra self-assurance.

Taking a few minutes to measure yourself thoughtfully is a simple but meaningful way to invest in your well-being. Just as we design reusable period care that’s better for you and the planet, our silky soft bralettes are made with responsibly sourced materials. After all, comfort shouldn’t come at the cost of your eco-conscious values.

When your fit feels right, you don’t have to think about adjusting, shifting, or second-guessing. You’re free to focus on what matters most: living with purpose and feeling like yourself. We are here to support you wherever you are in your journey, from period care to everyday underwear essentials. Because at Saalt, we are committed to providing you with care that feels good, both inside and out.

Read also:

• How Do I Know If My Bra Fits?
• What Age Should I Start Getting Mammograms?
• Bralette vs Bra. What’s The Difference?

Frequently Asked Questions About How To Measure Your Bra Size

How often should you measure your bra size?

Your body is always evolving, and that’s completely normal. Weight fluctuations, hormonal shifts, pregnancy, or just the passage of time can all influence your bra size. As a general guideline, it's helpful to measure yourself every 6 to 12 months, or anytime your current bra doesn’t feel quite right. Trust your body’s signals and give yourself permission to adjust. Comfort is not a luxury; it’s a form of care.

What is the difference between band size and cup size?

Think of your band size as the foundation. It’s the measurement around your ribcage, just beneath your bust. Your cup size reflects the volume of your breasts and is determined by the difference between your bust and band measurements. Both numbers work together to help create a fit that feels supportive, balanced, and uniquely yours.

What is sister sizing in bras?

Sister sizing is a helpful way to adjust your fit when you’re between sizes. It refers to bra sizes that share the same cup volume but have different band sizes. For instance, if a 34C feels too loose around the band, a 32D offers a similar cup fit with a more secure hold. Sister sizing gives you more flexibility to personalize your comfort, especially when one size doesn’t quite feel like home.

Why does my bra size differ between brands?

Just like bodies, not all bras are made the same. Design details, materials, and sizing standards can vary from brand to brand. A 36B in one style might feel more like a 34C (or even a 36A) in another. That’s why it’s helpful to focus on how a bra feels rather than the number on the tag. At Saalt, we design underwear and bras that flex with your shape and support you through life’s many shifts, because your fit should celebrate you, not box you in.

How can pregnancy or nursing affect your bra size?

Pregnancy and nursing bring powerful changes, including shifts in breast size and sensitivity. Hormonal changes can cause breast tissue to grow or retain more fluid, which may lead to frequent size fluctuations. During this time, it’s a good idea to check your measurements more often. Prioritize comfort and gentle support. You deserve to feel held through every stage.

What is the best time to measure your bra size?

Try measuring at the end of the day, when your body has naturally settled from movement and swelling. Wear a non-padded bra (or none at all), stand tall but relaxed, and take your time. Measuring isn’t just about precision. It’s about tuning into your body and finding a fit that feels good in real life, not just on paper. At Saalt, we’re here to help you choose what supports you best.