How to Calculate for Your Bra Size
Signs You Need a Better Fitting Bra
Do ya boobs hang low? Do they wobble to and fro? Does your band ride up your back? Do your shoulders drop the straps? Are you dealing with uncomfortable gaps in your cups or breast tissue spilling over the edges? If any of these sound familiar, you're likely wearing the wrong bra size—and you're definitely not alone.
Finding the perfect bra fit can transform not just your comfort, but your confidence too. This comprehensive guide will walk you through everything you need to know about proper bra fitting, from understanding how a well-fitted bra should look to calculating your exact measurements.
What Does a Properly Fitted Bra Look Like?
Before diving into measurements, it's essential to understand what proper bra fit actually looks like:
The Band: Should sit parallel to the floor around your torso and feel snug but not restrictive. You should only be able to pull it about one inch away from your body. The band provides 80% of your bra's support, so this fit is crucial.
The Cups: Should completely encapsulate your breast tissue without gaps or spillage. Your breasts should fill the cups completely, with no empty space at the top or sides, and no tissue bulging over the edges.
The Straps: Should stay comfortably in place without digging into your shoulders or sliding down. They should provide support without bearing the full weight of your breasts.
For Pumping Moms: When using wearable pumps, breast cups, or pump flanges, everything should create a complete seal against your breast without gaps or movement inside the bra.
Does Bra Size Change Over Time?
Absolutely! Your bra size isn't set in stone. Our bodies undergo significant changes throughout our lives, and several factors can impact your bra size:
Hormonal Changes: Pregnancy, breastfeeding, menstrual cycles, and menopause all affect breast size and shape.
Pregnancy and Postpartum: During pregnancy, your rib cage typically expands (affecting band size) while your breasts grow as mammary tissue develops. However, around 12 months postpartum, your rib cage usually returns to a smaller size, and weaning can cause temporary breast shrinkage as mammary tissue is replaced with fatty tissue.
Weight Fluctuations: Changes in overall body weight naturally affect both band and cup measurements.
Age: As we age, breast tissue changes, and our torso shape may shift.
Recommendation: Check your bra size every 6 months, and more frequently during breastfeeding and pumping periods.
How Bra Sizing Actually Works
Traditional bra fitting involved just two measurements: under the bust (band) and around the fullest part of the bust. However, modern fitting methods have evolved to be much more accurate.
The Advanced 4-Measurement Method: The Boob or Bust calculator uses four measurements—two for the band and two for the bust—to determine your best fit. This method is superior because it:
Captures migrated breast tissue from poorly fitting bras
Accounts for modern bra construction and design
Provides more accurate sizing for various body types
Understanding Cup Size Math: Cup sizes are calculated by subtracting your band measurement from your bust measurement. This means:
A difference of 4 inches = D cup
A difference of 6 inches = DDD/F cup
A difference of 8 inches = H cup
So while a "triple D" might sound large, it simply represents a 6-inch difference between your band and bust measurements.
Important Note: The calculator provides UK sizing, which differs from US sizing. Be sure to convert appropriately before purchasing.
The Reality of Bra Size Ranges
Bra sizes actually range from AA to P cups, but unfortunately, many manufacturers haven't caught up with this reality. Most women don't fit into the limited "standard" sizes that many brands offer, which can be especially challenging for nursing mothers who may have significant differences between their band and bust measurements.
Final Fitting Tips
Always check each brand's specific sizing chart before purchasing
Be aware that different colors in the same style may fit differently
Contact the company directly if you're unsure about sizing
Do a fit check before removing tags
Remember that proper fit is an investment in your comfort and health
The Bottom Line
Finding your perfect bra size isn't just about comfort—it's about supporting your body properly and feeling confident every day. Whether you're navigating postpartum changes, dealing with size fluctuations, or simply tired of uncomfortable bras, taking the time to measure properly and invest in quality bras will make a world of difference.
Remember, your bra size will likely change throughout your life, and that's completely normal. Regular measurements and quality bras are investments in your daily comfort and long-term breast health. If you’re feeling overwhelmed, then book with me so I can make this process simple for you.
Top Bra Brands for Nursing and Pumping Moms
The good news? Several brands have stepped up to create better options for moms. Here are the top recommendations:
The Amelia Cami is a favorite among many as it provides the support needed while being a relaxed PJ feel in a bra. The Amelia tank is also a great option for a full-length option. The Ella is a more structured option and is great for nursing or wearable pumping. The Riley is a pumping bra option for many that can fit into the size range.
You can use my referral code LIONESS to save. The brand or photos have affiliated links to open the website.
The Pumpkin is a pumping bra with a good size range to choose from and has a zipper closure for a more discreet and customizable pumping slit. Popping candy, rock candy, cotton candy, and ribbon candy are all styles that are great for nursing and some are supportive enough for wearable pumping too.
You can use my referral code LIONESS to save. The brand or photos have affiliated links to open the website. If you need the EU shop click here.
The original Sublime Hands-free pumping & nursing bra has branched out in sizing but is commonly known for how much fabric is involved. The Sublime Sports bra is another heavily favored pick from this brand, especially for wearables. The sublime lounge pumping bra is another option for a sleep bra for pumpers.
You can use my referral code LIONESS15 to save. The brand or photos have affiliated links to open the website.
These styles are all great for pumping, Pippa, Ayla, & Sydney 2.0. The big difference in these styles is how they will support different bust needs in the cup area.
You can use my referral code LIONESS to save. The brand or photos have affiliated links to open the website.
The Journey bra can be a great all in one option for those that fit this bra. The pumping slits provide a strong flange hold, the thicker band can support wearables well, and the Velcro straps allow for easy access for nursing. Unfortunately the sizing chart is not an accurate representation of the sizes it can accommodate.
You can use my referral code LIONESS15 to save. The brand or photos have affiliated links to open the website.
This brand is for those who need a heavy-duty sports bra for their wearable pumps/cups. The Low-impact style is the one we see the best results without crushing pumps into the breast.
Referral Link provides $10 off.
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