I Test Swimwear for a Living—These Are the Shopping Mistakes I'll Never Make Again

Why Swimsuit Shopping Feels So Overwhelming — And How to Finally Get It Right

For most people, swimsuit shopping ranks somewhere between doing taxes and rearranging a cluttered closet on the list of enjoyable activities. The fluorescent fitting room lights, the confusing size charts, the sheer volume of styles — it's a lot. But here's the truth: swimsuit shopping doesn't have to be so daunting. After years of professionally testing swimwear across dozens of brands, body types, and use cases, I've made nearly every mistake in the book so you don't have to. From buying the wrong fabric for your activity to ignoring return policies, these are the swimwear shopping mistakes I've learned to leave behind for good.

Mistake #1: Shopping by Size Instead of Fit

One of the single biggest errors shoppers make is treating swimwear sizing like they would regular clothing. A size medium in a T-shirt tells you very little about how a swimsuit in the same size will actually fit your body. Swimwear sizing varies enormously from brand to brand, and even between different styles within the same brand. I've worn everything from an XS to a large depending on the cut, the fabric blend, and whether the top and bottom are sold separately.

The smarter approach is to focus on measurements rather than labels. Before you shop, take your bust, waist, and hip measurements and compare them to the brand's specific size chart. If you're shopping for a one-piece, pay close attention to torso length — many brands now offer short, regular, and long torso options, and getting this right makes an enormous difference in both comfort and appearance.

Mistake #2: Ignoring the Fabric Composition

Not all swimwear fabrics are created equal, and choosing the wrong one for your lifestyle is a mistake that's easy to make when you're dazzled by a cute print. There are a few key things to understand about swimwear fabric before you buy.

• Chlorine resistance: If you swim laps in a pool, you need a suit made with chlorine-resistant fabric such as PBT (polybutylene terephthalate) or a high percentage of Xtra Life Lycra. Standard spandex and nylon blends will fade and lose elasticity within weeks of regular pool use.
• UPF rating: For long beach days or outdoor activities, look for swimwear with a UPF 50+ rating to protect your skin from UV damage. Not every suit offers this, and it's worth seeking out.
• Four-way stretch: This is essential for any active use — surfing, paddleboarding, water aerobics. A fabric that only stretches in two directions will restrict your movement and wear out faster.

Always check the fabric label before purchasing. A suit that looks perfect on a hanger can be a disappointment in the water if the material wasn't designed for your intended activity.

Mistake #3: Skipping the Try-On (or Not Trying It On Correctly)

Buying swimwear online without trying it on first is a gamble, but trying it on incorrectly in a store is almost as problematic. The most common in-store mistake? Keeping your underwear on during the fitting. I understand why people do it — hygiene concerns — but it genuinely prevents you from assessing the true fit of the suit, especially in the seat and hip area. Most swimsuits come with a protective liner for a reason. Wear it as intended when trying it on.

If you're shopping online, make absolutely sure the brand has a flexible return or exchange policy before you commit. Read customer reviews specifically for comments on fit and sizing — these are far more useful than the product description. Many shoppers will mention whether a suit runs small, has thin coverage, or shifts during activity, and that real-world feedback is invaluable.

Mistake #4: Choosing Style Over Support

A swimsuit can look stunning on a hanger and be completely impractical for actual use. This is especially true when it comes to bust support. Triangle bikini tops are perennially popular, but they offer minimal support for most cup sizes above a B. If you're active in the water, jumping waves or playing beach volleyball, an unsecured triangle top is going to cause more stress than style.

Look for suits with underwire, molded cups, adjustable straps, or a higher neckline if support is a priority for you. Brands now design incredibly attractive swimwear with full support built in — you don't have to sacrifice aesthetics for function. The best swimsuit is one you can actually move in confidently.

Mistake #5: Overlooking Care Instructions

You've finally found the perfect suit — now make sure it lasts. Neglecting proper swimwear care is a mistake that shortens the lifespan of even the highest-quality pieces. Always rinse your suit in cool, fresh water after every use, whether you've been in a pool, the ocean, or a hot tub. Chlorine, salt, and sunscreen are all highly damaging to swimwear fabric over time.

Never wring out your swimsuit or put it in the dryer. Both actions break down the elastic fibers and cause the suit to lose its shape. Instead, gently press out excess water and lay it flat to dry in the shade. Direct sunlight, ironically, can fade and degrade swimwear fabric even when it's out of the water.

The Bottom Line: Shop Smarter, Not Harder

Swimsuit shopping becomes significantly less stressful once you stop chasing a size number, start paying attention to fabric technology, and prioritize fit over fashion alone. Whether you're a casual beachgoer or a dedicated lap swimmer, there is a perfect suit out there for you — and avoiding these common mistakes puts you miles ahead in finding it. Take your measurements, read the reviews, check the fabric, and always, always try it on correctly. Your perfect swimwear season starts with a little more knowledge and a lot less guesswork.