Finding a swimsuit you love wearing isn't about having a certain body. It's about matching the suit to the body you have. At Swim City, our motto is "we fit customers, not labels," and once you know what to look for, the right fit gets much easier to find. Here's the Swim City guide to the details that make the difference.
Start With Honest Measurements
Swimsuit sizes vary a lot from brand to brand, so your everyday clothing size is only a starting point. Before you shop, grab a soft measuring tape and note:
- Bust: around the fullest part of your chest
- Underbust: snug, just below the bust (important for underwire and banded tops)
- Waist: at the narrowest point of your torso
- Hips: around the fullest part of your hips and seat
- Torso: for one-pieces, from the top of one shoulder, down through your legs, and back up to the same shoulder
Then compare your numbers with the specific brand's size chart. When in doubt, try two sizes, or ask us. Our team knows how different brands tend to fit.
The Cup-Size Rule Most Shoppers Don't Know
Here's one of the most useful things our fit specialists share: if a swimsuit doesn't say D, DD, E or "bra-sized," it's generally built for a B–C cup. An A cup will usually fit, maybe with a little room. B is the sweet spot, and C usually fits well. If you wear a D or larger, you'll usually be happier in a D/DD or bra-sized style than in a regular suit.
Signs you need a D/DD or bra-sized top
- You're spilling over the top or out the sides
- You feel unsupported, especially when you move
- The underwire sits on your breast tissue instead of underneath it
- You're constantly tugging and adjusting
- You size up to fit your bust, and then the rest of the suit is too loose
Where to find a better fit
For bra-sized and D/DD swimwear, look at Sunsets, Coco Reef, Bleu|Rod Beattie, Anne Cole and some Miraclesuit one-pieces. Some brands also cut their cups a little more generously even without a D/DD label, including La Blanca, Tommy Bahama, Jantzen, Longitude, some Miraclesuit and Magicsuit styles, and more.
Sister sizing: your secret weapon
If a top's cups fit but the band doesn't (or the other way around), try a sister size. Sister sizes have roughly the same cup volume on a different band:
- Band up, cup down: 32DD ≈ 34D ≈ 36C
- Band down, cup up: 34DD ≈ 32E ≈ 30F
So if a 34D feels right in the cup but the band rides up, try a 32DD. If the band digs in, try a 36C. Our team can help you find your sister size in store.
Bust Support: Find the Right Structure
Support comes from more than straps. Here's what each feature does:
Underwire
Underwire gives the most lift and shape, which makes it a good choice for fuller busts. Look for styles labeled by cup size (like D–DD) for a more precise fit.
Soft cups and shelf bras
Molded or removable soft cups add shape and modesty without wire. They're comfortable for smaller-to-moderate busts or anyone who dislikes underwire.
Straps and bands
Wider, adjustable or crossback straps spread the weight more evenly than thin ties, and a firm underbust band does much of the real work. Halters can lift, but some people find they strain the neck over a long beach day.
The fit test: the band should sit level and snug without digging in, cups shouldn't gap or spill, and you should be able to raise your arms without the top shifting.
Mix and Match: Tops and Bottoms Don't Have to Match
If you're a different size on top and bottom (and most of us are), look for suits sold as separates. Many brands we carry sell tops and bottoms individually, so you can pair a supportive top in one size with a bottom in another. Bleu|Rod Beattie, for example, offers styles like the Barcelona Bloom Underwire D-DD Cup Bra with coordinating bottoms such as the High Waist Skirted Bottom.
Other brands with mix-and-match separates include 24th & Ocean, Beach House, Anne Cole, Coco Reef, Sunsets, Kulani Kinis, Magicsuit, Tommy Bahama and more. A few tips for mixing sizes:
- Size each piece on its own. Pick the top by your bust and cup size, and the bottom by your hips.
- Stay in one collection when you can, so the colors and prints match exactly.
- Change the silhouette, too. A tankini top with a high-waist or skirted bottom gives you a one-piece look with two-piece flexibility.
Shop all swim tops, swim bottoms and more.
Long Torso? Look for Long-Torso Sizing
If one-pieces pull at the shoulders or ride up in back, you may need extra torso length. Some brands make dedicated long-torso styles. Our Longitude collection includes long-torso one-pieces like the Palm Dancer Long Torso Panel Tank, which also has a powernet front lining for tummy control. Tommy Bahama one-pieces are another good option for longer torsos. Two-piece styles like tankinis are an easy fix, too, because tops and bottoms move independently.
Tummy Control and Shaping Suits
Shaping swimsuits use firmer, higher-stretch fabrics and smart design to smooth and support. Some features to look for:
- Shaping fabrics: Miraclesuit uses its signature Miratex® fabric, with the brand promise "Look 10 lbs. lighter in 10 seconds." Try the Miraclesuit Tempest Oceanus, which combines Miratex with draped fabric that conceals the tummy.
- Powernet linings: an inner layer of firm mesh across the front panel for gentle control.
- Ruching, shirring and draping: gathered fabric that camouflages and flatters.
- Skirted suits and swimdresses: extra coverage with easy movement, like the Magicsuit Ellie Swimdress.
Miraclesuit vs. Magicsuit: which one?
They come from the same family, but they're built for different priorities:
- Miraclesuit: maximum control. Its Miratex fabric is all about firm shaping, and it's our go-to for the most flattering one-piece.
- Magicsuit: lighter control with a more fashion-forward feel, and more separates and tankinis to mix and match.
Our rule of thumb: if you want the most shaping in a one-piece, start with Miraclesuit. If you want fashion and flexibility, start with Magicsuit. Explore both, plus Longitude and more, or browse all women's one-pieces.
Fit Problems, Solved
Here are the fit complaints we hear most often, and what we suggest:
"My suit rides up."
That usually means the torso is too short for you. Try a long-torso one-piece from Longitude, a Tommy Bahama one-piece, or switch to a tankini so the top and bottom move separately.
"Most one-pieces are too short." / "I'm long-waisted."
Same fix: look for long-torso sizing. Longitude makes long-torso styles specifically for this.
"My straps dig into my shoulders."
Your straps are probably doing the job your band and cups should be doing. Try a D/DD or bra-sized top with a firm band, or wider, adjustable straps. In a one-piece, a longer torso can also take tension off the shoulders.
"I'm spilling out of the top."
Remember the cup-size rule: most suits without a cup size are built for B–C. Move to a D/DD or bra-sized style, or try a sister size.
"I'm a different size on top and bottom."
Shop separates and size each piece on its own. See the brands in "Mix and Match" above.
"I want more tummy control."
Start with Miraclesuit for maximum control or Magicsuit for lighter control, and look for powernet linings, ruching and draping.
"I want more coverage."
Try a tankini, a swimdress or a skirted or high-waist bottom. See "Coverage" below.
Coverage: Choose Your Comfort Level
Bottoms range from cheeky to full coverage, with leg cuts from moderate to high. A higher leg can visually lengthen your legs, while a moderate cut and full back offer more coverage. Higher-waisted bottoms add midsection coverage, and skirted bottoms add even more. There's no "right" answer, only what makes you comfortable.
Plus-Size Swimwear
Plus-size swimwear is engineered differently, not just made bigger. Look for stronger support, wider straps and fabrics with good recovery. Browse our women's plus-size swimwear.
Swimwear After Mastectomy
Mastectomy swimsuits include pockets designed to hold a breast form in place, often with higher necklines and soft bra linings for comfort. See our mastectomy swimwear, such as the Penbrooke Leopard Love Blouson Swimsuit. Our team can also help you find options in store.
How to Test a Swimsuit in the Fitting Room
- Sit down: does the bottom stay put and the torso stay comfortable?
- Raise your arms overhead: does the top stay in place?
- Bend and twist: does anything gap, pinch or slide?
- Check the straps: do they dig in or slip off?
- Look at the back: no sagging fabric and no straps cutting in.
A new suit should feel snug when dry, since swim fabrics relax a little in the water, but it shouldn't leave deep marks.
Found the Style but Not Your Size?
If the suit you love isn't in your size at your store, ask us. We can transfer it from another Swim City location or place a special order when the brand has it (either can take a few days or more). We can also hold items while you decide, or ship your purchase to your home.
Make Your Suit Last
Once you've found the one, take care of it: rinse in cool water after every swim, hand wash, and never put it in the dryer. See our full swimwear care guide.
Let Us Help You Find the One
Reading about fit helps, but trying suits on with help from people who do this every day is the fastest way to find the one. There's no appointment needed: stop by any Swim City store, and our team will be happy to help you find the right fit. Our stores carry far more styles than you'll find online. Find a location on our store locator, or call 1-800-210-6221 with sizing questions.
