Let's talk about a common pitfall in lingerie and swimwear design: using dress sizing for bras. On paper, it might seem like a simplified solution; less complexity, fewer SKUs, easy for the customer to understand. But in reality it creates a terrible fit experience for anyone who doesn't fall into a narrow "average" size window. And here's the thing: very few people are actually average.
When you use dress sizes (like S, M, L or 8, 10, 12) for bra fit, you're asking the customer to make a compromise. Do they want to fit the product to their ribcage or to their breast size? Because unless they happen to be, for example, a 34B (the rough fit that most size Small/10 dress-sized bras are cut for), it's not going to work for both.
Let's take an example: say someone is a 32DD. If they choose the small size to match their ribcage, they'll get a band that fits, but a cup that's far too small. Cue spillage, double boob and all-day discomfort. But if they size up to get the cup volume they need, the band becomes too loose. That leads to poor support, straps that slide off the shoulders and the back riding up. Neither option works, and yet that's the dilemma dress-sized bras force people into.
Dress sizing might simplify things for the brand, but it complicates things massively for the customer. A well-fitting bra isn't just a nice-to-have, it's the foundation of support, comfort, and ultimately confidence. And if you want a product that actually delivers on that, you need to use true bra sizing.
Many brands start with dress sizing as a way to dip a toe into a new category, especially in lingerie and swimwear, because it's quicker and cheaper; fewer SKUs, less development time, and no need to hire in specialist bra tech expertise. On the surface, it seems like a low-risk way to test the waters.
But here's the catch: if the product doesn't fit well, the customer isn't going to buy it again. They won't be comfortable, they won't feel supported and they won't come back for more. In fact, they're likely to return their purchase altogether. So while it may seem like you're reducing risk by simplifying the offering, you're also undermining your ability to get a true read on whether the category has long-term potential. Beacuse when a product fails on fit and comfort, it doesn't matter how beautiful the design is, the customer won't stick around to find out what comes next.
While true bra sizing delivers the more precise fit, there are scenarios where non-traditional sizing can work, particularly in categories like swimwear and wireless bras. Straddle-sizing (like 32D/DD, 32E/F etc.) can serve as a practical middle ground, offering more inclusive fit than dress sizing alone, while keeping the SKU count more manageable.
Is it still a compromise? Yes. But it can be a smart and informed compromise. Especially for brands testing a new category or looking to simplify SKUs for inventory and/or investment, straddling cup sizes allows for some flexibility without ignoring support entirely.
But it's important to note: although hybrid sizing might appear simpler, that simplicity only really applies on the inventory side. From a technical development perspective, it can actually be more complex. Why? Because now you're asking a single pattern to straddle multiple cup sizes, and that requires careful design, advanced grading logic and experienced garment techs to execute well. Furthermore, fit sessions need to be carefully planned, ideally on people who represent both ends of the intended size, e.g. 32D and 32DD models to fit a 32D/DD bra, to ensure the fit truely works for everyone it's meant to serve. So that means double the models, and therefore double cost, and overall a much more involved fitting process than brands might initially expect.
Yes, bra sizing adds complexity over dress sizing, there's no denying that. It means more sizes, more fittings, more technical knowledge, and therefore more investment too. But that complexity is where the value lies, because when you invest in proper sizing, you're not just making a better product, you're making a product that actually works for real people. You're offering support, comfort and confidence, and that builds trust. When a customer trusts your fit, they come back without hesitation. They'll buy the same style again in a new colour or fabrication, knowing it will deliver. From a business perspective, this translates to higher customer lifetime value, lower returns and more repeat purchases. You're not constantly reacquiring new customers, you're building a base of loyal ones who genuinely want more of what you're making. Bra sizing isn't just a technical investment, it's a growth strategy.
Starting out in bra sizing can feel like a minefield, especially if your team hasn't done it before. But the payoff in product performance and customer loyalty is huge. If you want to take your product to the next level and make the switch to bra sizing, get in touch. I can help you make sense of the sizing, build a product that works and support your team through the transition.
