What Size Is Considered a 'Plus Size Bra'?

If you’re a size 14 or 16 and wondering whether that means you need to shop specifically for plus size bras, we see you! Come on in, pull up a cosy chair. Tea? Coffee? We’re so glad we found you.

Clothes sizing is chaotic, and if we’re honest, bra sizing is no better. Especially when you start searching things like “bra sizing plus size” or “bra size for plus size” and end up with ten different answers. Every brand does it slightly differently, which means you might go to buy a bra in the size you usually wear and, nope, no joy. First of all, don’t blame your body. The chances are that it’s not a 'you' problem, it’s a bra problem.  

Most women who find this page arrive by Googling “what size is considered a plus size bra?” because they feel like standard stuff doesn’t work for them anymore and that maybe they need to cross over into a different category altogether. Well, you’re in safe hands here, because at Rose & Thorne, we have inclusive sizes from 10 - 24 and C - K. If you find a bra you love on our site, it’s almost certainly in your size (and if it’s not, it’s usually because a bunch of other women beat you to it). 

So, go! Be free and find a bra that makes you look and feel amazing! Oh, you still want an answer to your question? Ok, read on. 

 

What Size Is Considered a Plus Size Bra?

In most lingerie brands, a plus-size bra refers to bras with larger band sizes rather than larger cups. In New Zealand sizing, that typically means band sizes 18–24 and above. Cup size is separate, so someone could wear a 10G or a 22C, both may have similar breast volume but very different band sizes.

Because brands structure their ranges differently, “plus size bras” aren’t defined by one universal rule. What matters more is whether the bra has been designed with enough support and structure for the body wearing it.

 

Plus Size in Bras Is Mostly About Back Size

In clothing, plus size usually refers to overall body size. In bras, plus size is about the size of your band. In Australian sizing, that might mean sizes 18, 20, 22, 24 and above being grouped as “plus size bras”. But that doesn’t mean the cup size is automatically larger, and it doesn’t mean the bra itself should be fundamentally different in style.

Large cup bras have more volume in their cup for larger boobs, while plus-size bras have bigger bands for larger bodies. That’s important because a narrow band and straps may be fine for someone who wears a 10C, but if you have more curves or volume, those dainty little bras can become incredibly uncomfortable.

 

How Bra Sizes Actually Work

Bra sizes are made up of two parts: the band size and the cup size.

The band size (10, 12, 14, 16 and so on) relates to the measurement around your ribcage. The cup size (C, D, E, F, G and beyond) represents the difference between your ribcage measurement and your bust measurement.

This means cup size doesn’t exist on its own. A 10G and a 20G don’t carry the same breast volume, because the band size changes the proportions of the bra.

That’s why someone can wear a smaller band but still need a fuller cup, while another person might wear a larger band with a smaller cup.

What Happened To Inclusive Sizing?

One reason women search for “plus size bra suppliers” is that so many brands separate extended sizes into their own limited collections. Fewer colours. Fewer shapes. Fewer options. It’s all about cost saving, and not wanting to create bras that there’s a smaller market for. Well, we say that’s not good enough.

We’re firm believers that a good brand should cater for as many bodies as possible. Most of our styles run from size 10 through to size 24. That means you’re not pushed into a tiny “extended size bra” corner with limited options. You’ll get the same lace, the same colours and the same silhouettes. The only thing that differs is how much support we add to make sure the bra is comfortable for the wearer. 

We do have plus size bra collections, but they’re full of the same styles you’ll find elsewhere on the site, just in a prefiltered format for easier shopping.  

Don’t bother with a plus size bra size chart or a large bra size chart from different brands; our bra size chart is designed specifically for NZ sizing. 

What Actually Changes as Sizes Increase

As body and bust volumes increase, a bra needs to do more to earn its keep. And that’s where structure and support come in. The internal engineering of our bras follow our “Full Cup” design from C-G cup, and our “Premium Support” design from G-K.

Whether you’re a 10K or a 22G, Premium Support ensures the structure matches the volume. Bras have a firmer internal frame, a more upright C-shaped underwire that brings breast tissue forward for lift, and higher-cut cups for added coverage and stability.

With us, support scales with cup size, not body size.

Bras That Move With You

Bodies fluctuate. Hormones shift. Seasons come and go. 

For most of us, our weight is always moving up or down. That’s where rigid bras often fail us. And that doesn’t only apply to curvier sizes, but across the board.

Our Forgiving Fit™ technology is built into our bras at every size. It allows subtle flexibility through the cup and band, so your bra adapts to normal bodily changes, instead of punishing you for them.

So, What Size Is Considered Plus Size?

In technical terms, plus-size bras are usually those that are size 18+, regardless of cup size. Some brands will label anything above a certain band or cup as plus size bra sizes, but there’s no universal rule. And in practical terms, the label matters far less than whether the bra has been designed with curves in mind.

Ready to find something you’ll love to wear? Shop by bra size, or if you’re unsure which size to choose, our bra fit tools and online fittings can help you figure it out.

 

Common Questions About Plus Size Bras

Is plus size the same as large cup bras?

No. Plus size bras usually refer to larger band sizes, while large cup bras refer to larger cup volumes. Someone can have a small band and large cup, or a large band and smaller cup.

Is a 16 bra considered plus size?

Some brands begin their plus size ranges at band size 16, while others start at 18. There is no universal standard, which is why finding a brand with inclusive sizing across multiple band sizes can make bra shopping much easier.

Do plus size bras need different support?

Support should scale with breast volume rather than clothing size. Larger cup sizes need deeper cups, stronger internal frames, and supportive underwires to distribute weight comfortably.