Why Most Women Wear The Wrong Bra Size And How New Tech Is Changing Fit

Varsha Anjali speaks to lingerie designers and researchers in New Zealand to find the answers.

For those of us who wear them, bras are something we strap on almost every day. So why do so many of us still struggle to find a comfortable one?

According to Viv Baartman, chief executive of UunaFit – a New Zealand company that uses AI tech and 3D knitting to create custom-fit bras – it’s because bra designs mostly cater to “the average body”.

“But no woman is average,” Baartman tells Viva. “Our bodies vary in countless ways: shape, proportion, movement, and even how we change over time. Yet the industry has kept women squeezed into a sizing system invented nearly a century ago. The result? Around 85% of women are in the wrong size, and nearly 7 in 10 experience daily discomfort.”

Helen Cloke, owner of the Taranaki-based lingerie supply shop Nellie Joans, agrees.

“Our bodies are too diverse for a one-size-fits-all approach. That’s why sewing your own bra – or having one custom-made – is such a powerful alternative. You can tailor every element to your body and preferences”.

And if you have a sewing machine and the right materials, there are an abundance of free bra patterns for DIY purposes.

The most common bra sizing system involves measuring the underbust (around the ribcage) for band size and the overbust (the fullest part of the bust) for the cup size. But, according to Baartman, many women also don’t fully understand their correct size or how to find a well-fitting bra, “often relying on self-measurements or fitting assistants that can be inaccurate”.

Adding to the confusion, Baartman says some brands promote unrealistic body shapes in their marketing, which can impact customers’ confidence, posture, and even long-term health – particularly for breast cancer patients who undergo mastectomy.

“For women after [breast] surgery, the impact can be even more stark: many are left with limited, clinical options that don’t honour their needs or restore dignity. Add to that the fact that returns and discards from ill-fitting bras feed fashion’s waste crisis, and you can see it’s not just women being failed; it’s the planet too.”

Chloe Julian, fashion lingerie designer and founder of Auckland-based Videris, finds some women still equate “support” with “discomfort”.

“When I was fitting women during the development of [our] bras, I found that the idea of a bra that felt supportive yet like wearing nothing was confusing for a lot of women,” she explains.

“It was almost like, unless the bra felt tight or uncomfortable, they didn’t feel supported. Traditionally, support meant holding, restricting, pushing breasts up, and keeping them still, often through wires and rigid structures. But for me, support is about embracing your natural form and moving with the shifts your body makes throughout the day.”

Cloke, who worked in landscape design for 16 years before establishing Nellie Joans, believes the sizing system is “more complex and less standardised” than people realise.

“Underwire shape plays a massive role in fit, and unfortunately, most ready-to-wear brands can’t offer the variety needed to accommodate everyone.

“That’s one of the biggest advantages of sewing your own bra: you can find your perfect underwire and build from there,” she says.

The creators of UunaFit, which won the 2025 Wellington Gold Award for Innovation, argue the tech they use captures the “true geometry of the body” that replaces “outdated, unreliable and confusing” sizing charts.

“Our approach uses secure 3D body scanning via smartphone to capture the unique shape of each person’s torso,” explains UunaFit co-founder and Victoria University associate professor Edgar Rodriguez Ramirez.

From this data, the company’s custom-built and private AI algorithms extract precise measurements and generate a made-to-measure digital manufacturing pattern. These patterns are then sent directly to state-of-the-art 3D knitting machines, which produce seamless, zero-waste bras tailored individually.

“This process not only ensures unmatched comfort and fit, but also eliminates excess stock, avoids sizing confusion and dramatically reduces textile waste.”

“The next step is wearer trials,” adds Baartman. “Later this year, we’ll be inviting women who have undergone breast cancer surgery to test our first post-surgical bras. Their feedback won’t just fine-tune the fit; it will shape the design and experience in ways that honour both physical and emotional needs.”

So, we know what doesn’t work, but what are the key elements that make a great bra in 2025? While the designers Viva spoke to had different answers, some themes were similar: movement, individualisation, and genuine comfort.

“For me, it’s all about comfort and genuinely respecting a woman’s body and shape without trying to change, conform, or compress it,” says Julian, who led the design team for Rihanna’s lingerie line, Savage X Fenty. “A piece that moves with you, not against you.”

Lu Blade-Bittle, co-founder of NZ luxury lingerie brand Ohen, argues women now want both “comfort and pieces that feel feminine and are thoughtfully made”.

She says it comes down to the “perfect balance of fabric, wire and design”.

“We developed a custom underwire that’s a little softer and more flexible, so it moves with you while still offering support,” she says.

Even though wireless bras are becoming more popular, Cloke says she’s still a fan of the underwired bra – despite its “bad rap”.

“Once you find the underwire shape and size that fits your body, it becomes a second skin,” she says. “I wear mine all day without even thinking about it. The key is a personalised fit, and it starts with the right wire.”

For Baartman, a really good bra gives more than physical support – she says it restores confidence. “Comfort is the foundation: the bra should move with your body, not against it. It should fit like a glove – actually like a bra should.”

There’s also an emotional element to it, she adds. “For some women, a bra can mean dignity after surgery; for others, it’s the foundation for performance in sport; and for all, it’s simply an everyday comfort necessity and confidence booster.”

The past decade has seen exciting changes in bra design, influenced by advancements in sustainable fabrics, technology, gender attitudes and changes in lifestyle habits. Designers argue more can always be done.

“There’s always room to innovate in lingerie,” says Blade-Bittle. “From strapless bras that stay perfectly in place, to designs tailored for different sizes and breast shapes, it’s about creating pieces that combine flawless support with effortless beauty.”

And while sex appeal is not a priority for these emerging brands, it is being redefined.

“Function used to be the quiet compromise in lingerie design. You’d buy something for how it looked, even if it dug in or didn’t breathe. Now, comfort, breathability and support are expected, and form needs to work in harmony with those qualities,” Julian says of Videris’ designs.

“In fact, when something is well-designed and fits beautifully, that’s inherently sexy.”

Cloke similarly believes that “sexiness” is being reclaimed by the wearer: “It’s no longer about external validation, but about feeling empowered and confident in your own skin.”

Timeline of the bra