How To Buy A Bra Online That *Actually* Fits

Like a lot of time-strapped 40-ish women in North America, I’ve become an expert online shopper. I can reliably pick out something that fits in almost any category: coats, bathing suits, even shoes—no small victory, since my feet are shaped like loaves of bread. But if there was one thing I was sure I could never buy online, it was a bra. I couldn’t even buy one in a brick-and-mortar store without the help of a professional fitter, measuring, shoving, adjusting, shoving and measuring again, before insisting the rib-crushing one she had squeezed me into was the perfect fit.

It was the one retail outlet I couldn’t quit—until this year, when the sandwich generation thing hit hard and time became a scarce commodity. The control I once had over my life was hanging by a thread—as were my boobs, barely supported by the worn-down bras I had purchased four years prior.

I had no choice but to dive into the world of online intimates. After a perfunctory amount of research, I decided to focus on two companies that were getting a fair amount of love online: Toronto-based Knix and San Francisco–based ThirdLove. I got out the measuring tape, stood half-naked in front of the mirror and, for possibly the first time in my life, actually inspected my breasts. I’ve struggled with body image issues my whole life, so this was… not easy. But if I was going to become my own professional fitter, I had to get right in there.

I fumbled around with a measuring tape—the kind that belongs in a toolkit—and revisited the ghosts of bras past while following the brands' online size guides. In the end I made an educated guess, closed my eyes and clicked “Buy”.

When the bras arrived on my doorstep, I was doubtful they’d actually fit. And I was right. One was much too tight, the other way too gape-y. But both companies had stellar customer service at the ready. These women, also known as fit stylists, know boobs. They asked what was working, what wasn’t, had me re-measure myself in real time, managed my anxiety and sent new boxes of perfectly fitted bras my way, all in less time than it takes to watch one episode of Succession. The price point was a bit higher than I was used to—especially with ThirdLove’s shipping fees and duty—but it felt worth every penny. I was hooked.

Curious and a little awestruck—I’d never had one bra, let alone four of them, fit so well—I asked the pros at both Knix and ThirdLove about what makes a successful online bra-shopping experience. Rule #1: Your boobs, they are a-changin’.

Just because you were once a 36C doesn’t mean you’re still a 36C

The number one misconception people have about their breasts is that they stay the same size throughout adulthood, says Ra’el Cohen, chief creative officer of ThirdLove. “A woman’s bra size typically changes about six times in her life.”

People with larger cup sizes are definitely prone to make this mistake, says Knix founder Joanna Griffiths. “They become conditioned to going to stores where their true size isn’t being carried. So, we see women who are an E or F or G cup or beyond, who think that they’re more like a double D.”

Both Griffiths and Cohen cited a study that found 80 percent of women don’t know their true bra size—so keep that measuring tape handy. (Griffiths offers this pro tip: If you don’t have a fabric measuring tape, run a piece of string or ribbon around your chest, then measure it with a ruler.)

Be prepared to let go of other long-held beliefs

The success of Knix has proved that many women don’t in fact need underwire for support. The company bet big on creating comfortable, supportive, wire-free bras—and Griffiths notes that more than 70 percent of their sales are for D cups or larger.

It might take some trial and error to find the right style for you

“Different styles may work better for different women, depending on breast shape and where her breast tissue sits,” says Cohen. Women with round shapes and larger breasts might feel more comfortable in a style that provides full coverage, for example, which distributes the breast tissue evenly across the bra. “There’s been a shift in the apparel industry to dress a woman’s shape, not necessarily her size,” Cohen adds. “We’ve seen this in jeans and dresses, where companies look for a fit that is flattering based on shape, and breast shape is no different."

Lean in to the online fitting tools

They are designed to help. ThirdLove’s FitFinder is a quiz that asks a series of questions about the fit of your current bra and unique breast shape. It recreates the accuracy of an in-store fitting, Cohen says, and uses algorithms built by their female-led data science team to recommend a size and style. The quiz gets smarter the more women who take it (more than 14 million have so far) and ThirdLove’s lines have expanded to offer 78 different sizes.

Griffiths has noticed that women are better at identifying what shape they are when given examples to choose from—but they often fall into a couple of categories. “Maybe they have bell-shaped breasts, but they are also asymmetrical,” she says. If forced to choose, go with the option that speaks most broadly to your overall shape.

When it comes to band size, you may want to size down

The most common mistake women make is wearing a band size that’s larger than needed, Cohen says. That can lead to some pretty major discomfort. The band is the main source of support—it should be snug.

When they arrive, do a three-point check on the fit

“The cups should form to the curve of your breasts without gaping or digging in,” Cohen says. “The straps should sit snugly on your shoulders without leaving indentations on your skin and the band should feel comfortably snug around your body without hurting.” (Make sure it’s on the loosest hook, she adds—this way, you can tighten it as the band naturally stretches over time.)

The little details can make a big difference

Padded straps, soft materials and even small details like tag placement can make a huge difference when it comes to comfort. The goal here, Cohen reminds, “is to forget you’re wearing a bra at all.”