The Dos and Don’ts of Proper Bra Fitting 

by Jaclyn McCabe October 24, 2019


Here's a fun fact: if your bra is the thing you can't wait to take off at the end of the day, you're wearing the wrong size. The truth is, you shouldn't be thinking about your bra at all. But if you are, please know you are not alone. Eight out of ten women aren't wearing the right size bra, and we don't even know it. 

Sachi Bra by Elomi Plus Size Bra Full Figured Bra

Sachi Plunge Bra by Elomi
Available in Black Cup D-G $64


We've all heard a properly fitted bra is essential. We know it adds a level of comfort to your day, as opposed to the stress a jabbing underwire adds. It also has the power to change your entire wardrobe! With your girls resting comfortably halfway between your shoulder and your elbow, your bra creates a complimentary silhouette for all your clothes to fit better. 

So why do we frequently walk away from bra shopping with a cute piece of lingerie that just doesn't provide real support? Part of the issue is that we tend to buy what's cheap and easy instead of investing in thoughtfully crafted quality pieces. But even the fanciest bra will fail you if it doesn't fit your body correctly.

Like most of us, you probably wandered into a mall store once as a teen and had a sales assistant wrap a measuring ribbon around your chest and mumble something about your cup size. Then, if you were bigger than a DD, they stuffed you into the biggest band size they had in order to make a sale. 

Here's the thing, nineties hip-hop lied to us—DD is not big! Nor is it even average for a plus-size woman. It's actually on the small size of the spectrum. At Jaci Blue, we find our average customer's cup size is a G cup.

At the mall, no one ever told us the truth or sold bras bigger than a DD. So we bought what was given to us, never even knowing there were other choices out there, and moved on. 

Luckily, with a few simple tips, you can find the perfect bra for your unique shape.

Cate Bra by Elomi Plus Size Bra Full Figured Bra

 Cate Bra by Elomi
Available in Latte, Black and Peacan Cup DD-K $59


Measure Like a Pro 

To get the right band measurement, wear a very lightly-lined bra; i.e., nothing padded or molded. Wrap a measuring ribbon around your body right under your breasts, keeping the front parallel to the back. This measurement is your band size—it’s the numbered part of a bra size. If you have an odd number, round up to an even number.

To get an accurate reading of your bust size, place the tape at the fullest part of your bust. Make sure the tape is parallel around your front and back for this part, too. 

Then subtract the band size from your bust size to get your cup size, the letter part of your bra size. Each inch indicates one cup size. 

For example, a band measurement of 39" and a bust measurement of 46" leaves a difference of 7”. Beginning with A, count up seven letters for a final bra size of 40G.

Be mindful that this is just a starting point. Just like in clothing, sizing is a suggestion. It is always necessary to try a bra on before you buy it.  This is because the sizing varies by designer, style, and the country they are made in. We actually use the UK sizing at Jaci Blue. It's a more streamlined way of sizing than US bra sizing.  


Deauville Bra by Primadonna Plus Size Bra Full Figured Bra

Deauville Bra by Primadonna
Available in Café Latte or Black Cup B-J $142 


Finding "The One" 

So now you know where to start. That's great! Here are a few pro tips to consider when you’re searching for the perfect fit.

Are the girls really in?

Most of us aren't mindful of how our breasts fall into the cup; once it's on, it's on. But if you take a moment to adjust your breast tissue, it can make a world of difference. We suggest taking your right hand and holding the underwire on the right side in place. Then place your left hand inside the cup and scoop your breast up and over toward the middle. Do the same for your left breast. This action ensures all your breast tissue is inside the cup,

Does the cup fit? 

If the cups are too roomy, move down a cup size. If the cups are cutting into your breast tissue causing a "double boob" effect, try moving up a cup size. If it’s close, you can play around with a style that has a deeper cup. If the edges of the cups lie smoothly against your breasts with no loose fabric or spillage, you're winning.

Are the straps digging in?

Straps should provide only ten percent of your bra's support; the majority of the support should come from a great fit in the band. If you're relying on your straps for more support than this, you probably need to move down a band size. If your breasts aren't very full on top or tend to droop, find a rounder cup style as opposed to a deeper cup

Is it still comfy when you sit?

Our rib cages open when we sit, so always test out a bra by sitting and standing. An arched center panel is a cute embellishment that can also ensure a comfortable cut if your belly moves upwards when you sit. 


Couture Bra by Primadonna Plus Size Bra Full Figured Bra
Couture Bra by Primadonna
Available in Cream or Black Cup Sizes C-J $132 


Bra Hacks 

Accommodate that time of the month

The shape and size of our bodies can fluctuate throughout the month, and that's pretty awesome. Honor your body by respecting its natural, cyclical changes! When you're figuring out your regular bra size and your period bra size, remember that you'll see a more dramatic difference from changing up your band size and a more subtle difference from changing up your cup size. Band sizes differ by two inches and cup sizes by one inch, so if you just want to make a minor tweak, focus on adjusting your cup size first. 

Buy one bra size for regular days and another size to accommodate your monthly cycle. Trust me, your boobs will thank you.

Join the sisterhood of sister sizes 

If your cup and your band aren't fitting quite right, or that super cute bra doesn't come in your exact size, look to your sister sizes. Sister sizes are groups of bras of different sizes that have equivalent cup volume. Check it out: if you wear a 40G, you may also find a good fit wearing a 42F or a 38H. For your convenience, we have a guide that details the correlating sister sizes between our super cute Prima Donna and Elomi brands.  

Double-check with us

I've been a certified bra fitter for more than ten years. But before that, I didn't know I was wearing the wrong size until my friend pointed it out when we were getting dressed in a hotel room on a trip. Once I figured out my true size, I was floored. I didn't know bras were supposed to be comfortable!

If you think you’re wearing the wrong bra, don’t worry. Jaci Blue can help. 

Sister Size Bra Chart Elomi Primadonna Goddess


Photos by Jennifer Zdon of Twirl Photography

Jaclyn McCabe
Jaclyn McCabe


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Size Chart

Clothing Chart

How to Measure

Measure around your body under your arms and over the fullest part of your bust.

Measure around your body at your natural waistline. Keep the measuring tape comfortably loose.

Measure around the fullest part of your hips, placing the tape around midway between your crotch and belly button.

Take a pair of pants that fit you well and lay them flat. Measure the distance along the inner seam between the crotch and the hem.


Bra - How to Measure

Step 1: Measure your band size.

With your bra on, measure firmly around your rib cage, underneath your breast. The measuring tape should be parallel with the ground. Please reference chart below for band measurements.

Step 2: Measure your cup size.

With your bra on, measure the fullest part of your bust. This works best with a non-padded bra. Make sure the tape is taut and straight. 

Step 3: Calculate your bra size.

Subtract your band measurement from your cup measurement. Generally, for each inch in difference, the cup goes up by one size.
Range 29"–32" 33"–34" 35"–39" 39"–41" 42"–43" 44"–45"
Size 34 36 38 40 42 44


Step 1: 33" = 36 Band

Step 2: 38"

Step 3: 38" - 33" = 5", which is an E cup size in Prima Donna or DD in Elomi

Step 4: Refer to Sister size chart to see equivalent cup sizes by brand

Sister Size Chart

PrimaDonna Elomi

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