What Size Swimsuit Should I Buy?

Shopping for shoes? I could do that all day. Shopping for a new swimsuit? Well, it’s an expedition I’d have to steel myself for. All my worst body anxieties will come to the surface. Plus, I’ll also have to contend with not really knowing what size of style is right for me. 

Some of us haven’t bought a new swimsuit in years, so we’re not in the habit of seeing ourselves in new swimsuit styles or knowing what’s right for our bodies now. But when it comes to sizing, there are some tips. Let’s explore...

Knix Swimwear Sizing

First, let’s get the product pitch out of the way ;)

Knix has recently launched a fantastic range of swimwear, and also period swimwear. You can find size charts specific to each suit on every product page. Here’s what they look like:

You can also book a Virtual Fitting. But regardless of what brand you’re shopping for, here’s some useful advice:

Tips For Swimsuit Sizing (No Matter What Brand)

So, no matter what brand you’re shopping from here are some general pointers:

Start With Your Regular Size

Swimsuits, like most garments with a lot of stretch, often look misleadingly small on the hanger. So don’t judge too much based on their appearance on the hanger. 

The best jumping-off point is the size you typically take. For swimsuits, this may be indicated as small/medium/large, etc., or in traditional sizes like size 4, 6, 8, 10, 12, etc.

While sizing is rarely standard across brands and most of us go up and down across brands, this is the best place to start...

Consult the Size Chart & Whip Out Your Tape Measure

To get a clearer understanding of the sizes, pull up the size charts on the website you’re on. Most websites will have a size chart linked in the product details of individual items.

Depending on the retailer, the size charts might include measurements for bust/underbust, waist, hips, and torso length. Measurements may be in inches or centimeters. 

To take accurate measurements, it’s best to use a fabric (seamstress) measurement tape and take the following measurements:

• Bust: To get this measurement, measure over the fullest part of your bust, with the tape measure parallel to the floor. 
• Underbust: This measurement will especially matter for underwire swimsuits or bikini tops. To get this measurement, measure directly under your bust, with the tape measure parallel to the floor. 
• Waist: This is the measurement around the narrowest part of your natural waistline.
• Hips: This is the measurement around the fullest part of your hip, before the thigh begins to narrow. 
• Torso length: Torso length is important for swimsuits. You get this measurement by taking a measurement from your shoulder to the crotch, at a measurement.

Compare the measurements you come up with with the size charge. Remember to read the size charts carefully to make sure you’re adhering to any particular measurement directions.

If You’re Between Two Bathing Suit Sizes, Go Small

Swimsuits usually have a lot of elastication and stretch over time, and when wet, so if you’re right between two sizes, you’re likely safe going small. 

That said, going for a smaller swimsuit size shouldn’t push you into an uncomfortable experience. So if you notice any uncomfortable compression or red marks on your skin, or find the suit difficult to get on and off, it’s likely you’ve gone too small.

Related: Where to buy plus size swimwear

Order Multiple Sizes (Checking Returns Policy)

Note: Different retailers will have different return policies (especially when items are on sale), so check that before trying this tip. Knix Swimwear is eligible for a return or exchange within 30 days of delivery and with the original sanitary strip and tags attached.

But assuming returns are easy, you might consider ordering multiple sizes (your size and the sizes up and down from it) so you can try them on in the comfort of your home. Once you’re confident you’ve found the right size, return the others.

Try Swimsuits at Home

Always try on your new swimsuit at home (even if you already tried it on in-store). There’s something about being at home, where you’re most comfortable, and trying on clothes that will give you a better sense of whether items fit correctly and are comfortable.

You’re familiar with the lighting and with your own mirrors. Plus, you’ll feel less rushed and even get a second opinion, if you want one. 

Two-Pieces Let You Pick Two Sizes

Two-pieces have the advantage of being sold as two separate parts, which means you can order a top and bottom in different sizes. If your body is two different sizes (e.g. you have a very full bust but narrow hips, or wide hips and a small chest), this may be an easier option than a one-piece which is designed for more uniform sizing.

Size Matters, But So Does Swimsuit Style

Getting the size right is an essential part of buying any garment. But when it comes to fit, style matters too. You might be wearing the right size in a swimsuit but not like it on your body, feel it cinches in all the wrong places or is generally not comfortable.

We all have unique bodies and we all want different things from our clothing, so a style you like on a website or hanger, might not feel great once you put it on. While we’re not here to say who (or what body type) should wear what style of swimsuit, here are some of the options:

Classic Leakproof One-Piece Swimsuit

If you love simplicity, a classic one-piece is the ultimate basic. Also known as a maillot swimsuit, this style is sleek and unadorned. It may (or may not) contain hidden support for your breasts. For some, the lack of adornment will make them feel more ‘exposed’ in this style. But if you’re a swimmer, this style will make sure nothing gets in your way.

A Plunge Neckline Swimsuit

A plunge neckline is almost universally flattering. Plunge necklines often feature wider shoulder straps, which will give you added support, while still being sexy. Check out our Deep V One Piece Swimsuit as an example of this style!

A Balcony-Style Swimsuit

If you like more structure and support, a balcony-style swimsuit offers a polished and sexy take on a classic swimsuit. Check out our Balcony Cup One Piece Swimsuit!

Swimsuits With Cut-Outs

Cut-outs are another way to soften a swimsuit. Peekaboo cuts at the front of back can give you a sexier look while still offering the coverage of a one-piece. If you’re worried about a one-piece looking old-fashioned, cut-outs are a great way to spice it up. Our Leakproof Wrap One Piece is a great option. 

Two-Piece Swimsuits

Two-piece swimsuits come in a huge variety of styles. 

You can have bottoms that are:

• Bikini shape
• Boyshorts
• High rise

And tops that include:

• Tank top (tankini)
• Pull-on bralette style
• Wired or underwired

Plus all kinds of design styles, colors, and embellishments!

It’s really a personal choice if you prefer a one-piece or two-piece swimsuit. But if you find it difficult to find a one-piece that fits you, the mix-and-match approach of a two-piece may work better for you.

Notes on Details and Fit

When it comes to swimsuits, the details count. Look for:

Adjustable Straps Will Help if Your Torso is Long or Short

If straps (either neck or shoulder) are adjustable, you’ll be able to better fit the swimsuit to your torso and to tighten it over time as it loses some of its elasticity. Related: How tight should a swimsuit be?

Wider Straps Will Give You More Support

Also, look for wide straps if you need a little more bust support. String or tie straps may dig into the skin and become uncomfortable if they’re supporting a larger chest.

Molded Cups Also Offer Support

Many swimsuits now offer “secret” support with built-in wireless bras and molded cups. These are great for keeping you in place and minimizing bounce and movement, while also giving you the silhouette you desire.

Remember, You Can Mix & Match Separate Bikini Sizes

Again, remember that with two-piece sets (or bikinis) you can choose a different top and bottom and mix and match. This means you can separately think about what’s flattering and comfortable on your bottom half, versus what’s supportive on your top. It also allows you to change your look with more combinations of styles and colors of pieces.

Finally, Don’t Forget: Start Shopping Early!

If you’re shopping for swimwear, get there early. At the height of the summer or during the winter travel season, you may find a lot of options have already sold out. It’s always good to have a great swimsuit handy, so start shopping early in the season and you’ll be all set for when those beach or pool days start!

We hope you found this post informative — but remember: we’re not doctors and this post is not medical advice! While all posts are fact-checked and well researched, we always recommend you chat with your doctor about any questions or concerns you might have regarding a medical condition. We’re here to support and educate, but never with the aim of disregarding professional medical advice you’ve been given. Phew, now that that’s out of the way, you can go on living unapologetically free.