Women’s Swimwear Size Guide & Size Chart

Swimwear sizing can be surprisingly tricky. The size you wear in everyday clothes won’t always be the size that works best in a bikini or swimsuit, especially when different brands use different fits and fabrics.

Your body measurements can give you a useful starting point. Bust support matters too, particularly if you’re shopping for bra-sized swimwear. Liza Clifford offers supportive, bra-sized bikinis and swimsuits, so knowing your bra size can make finding the right swimwear fit much easier.

Below, we’ll show you what to measure, how swimwear sizing works and what to look for once you try a piece on.

How to Measure for Swimwear?

Use a soft measuring tape and stand in a relaxed, natural position. Keep the tape flat against your body without pulling it tight.

You won’t necessarily need every measurement for every type of swimwear. Bikini tops are mainly about the bust and underbust, while bikini bottoms rely more on your waist and hips. With one-piece swimsuits, torso length can make a noticeable difference too.

Bust Measurement

Wrap the tape around the fullest part of your bust. Make sure it's sitting flat against your body and not squishing your breasts.

If you're looking at supportive or cup-sized swimwear, this is one of the key measurements to get right - it helps you figure out how much room you need through the cup.

Underbust Measurement

Measure around your ribcage directly underneath your bust. You want the tape to feel snug, but not like it's cutting off your breath.

This measurement is key for the band size on bra-sized bikini tops and supportive swimsuits. A good band should sit securely around the body because that's where most of the support comes from.

Waist Measurement

Your natural waist is the narrowest point between your ribs and hips. Wrap the tape around this area while you're standing up normally.

Don't suck your stomach in while measuring - you want a number that reflects how the swimwear is actually going to sit when you're walking, swimming or just relaxing.

Waist measurements are particularly handy when choosing high-waisted bikini bottoms and fitted one-pieces.

Hip Measurement

Stand with your feet together and measure around the fullest part of your hips and bottom.

For bikini briefs, this measurement is often more helpful than relying on your normal clothing size. Different cuts also sit differently, so a fuller brief may fit differently from a low-rise or high-leg style even in the same size.

Torso Measurement for One-Piece Swimsuits

Start at the top of one shoulder, take the tape down the front of your body, through the legs and back up to where you started.

It may sound like an odd measurement, but torso length matters a lot with one-piece swimsuits.

If the suit is too short through the body, it can tug at the shoulders, ride up or cut in. If it’s too long, you might notice loose fabric around the waist or a fit that feels a little saggy.

How Does Liza Clifford Swimwear Sizing Work?

There isn’t one single size system used across every Liza Clifford swimwear product.

Different brands and styles are sized in different ways. Depending on what you’re looking at, you may see:

• Bra-sized bikini tops and swimsuits, such as 32F or 36G

• Bikini bottoms in standard clothing sizes

• Sizes such as XS, S, M and L

That’s why it’s worth checking the sizing details shown on the individual product page rather than assuming one size will work across the full range.

If you’re shopping for supportive or cup-sized swimwear, your correctly fitted bra size is usually the best place to begin.

Women's Swimwear Size Chart

Swimwear tops and bottoms use different sizing systems. At Liza Clifford, tops use bra sizes, with band sizes from 28–44 and cup sizes from B–K, while bottoms range from XS–4XL. Available sizes vary by style.

Swimwear Top Sizing

Refer to our bra size chart for guidance on band and cup sizing. Your professionally fitted bra size provides a starting point when choosing a bikini or tankini top, although fit can vary between brands and styles.

Swimwear Bottoms Size Reference

Compare your waist and hip measurements with the approximate reference below. Measure around your natural waist and the fullest part of your hips, keeping the tape level without pulling it tight.

Check the sizing guidance for your chosen product before ordering. If you’re unsure which size to select, book an in-studio or virtual fitting for personalised advice.

Bra-Sized Swimwear

Supportive swimwear often works more like a bra than a standard piece of clothing.

Instead of choosing small, medium or large, you may choose a band and cup size such as 32F, 34G or 36FF. That gives you more control over how the swimsuit fits around your ribcage and across your bust.

If you already know your correct bra size, use that as your first reference point. You may still find that one brand fits slightly differently from another, so pay attention to the actual fit rather than only the number on the label.

If you’re unsure, a professional fitting can make the process much simpler.

Bikini Bottom Sizing

Bikini bottoms usually follow clothing sizes or an XS–XL system rather than bra sizing.

Your waist and hip measurements will normally give you the clearest indication of where to start. From there, think about the shape of the brief as well. A high-waisted bottom and a lower-cut style can feel quite different even when both carry the same size label.

The good thing about separates is that there’s no need for your bikini top and bottom to match in size.

How to Choose Your Swimwear Size From Your Measurements

Once you’ve taken your measurements, compare them with the size information for the specific piece you’re considering.

For bikini tops, look at your bust, underbust and cup requirements.

For bikini bottoms, your waist and hips are usually the most useful measurements.

For one-piece swimsuits, check your bust, waist, hips and torso length together. A one-piece has to fit the whole body, so one measurement alone doesn’t always tell the full story.

If your top half and bottom half fall into different sizes, that’s completely normal. Bikini separates let you choose each piece independently.

And don’t assume that because you wear one size in one swimwear brand, you’ll wear the same size everywhere else. Small differences in cut and fabric can change the fit more than you might expect.

How Should Swimwear Fit?

The right swimming costume for ladies should feel secure without feeling restrictive, while still allowing comfortable movement in and out of the water

You should be able to move around, sit down, lift your arms and swim without needing to constantly pull things back into place.

With supportive swimwear, the bust should sit comfortably inside the cups without being squashed or spilling out. The band should stay firm around the body, while the straps should feel comfortable rather than digging into your shoulders.

Signs Swimwear Is Too Small

• Digging into the skin

• Breast tissue spilling from the cups

• Cups flattening the bust

• Pulling excessively at the shoulders

• Riding up

• Restricting movement

Signs Swimwear Is Too Large

• Gaping around the cups, neckline or back

• Sagging when wet

• Excessive wrinkling or loose fabric

• Moving or shifting during swimming

• Providing insufficient bust support

Does Swimwear Sizing Differ Between Brands and Styles?

Yes, and sometimes quite noticeably.

Swimwear sizing isn’t completely standard across brands. You may wear one size in one collection and need something different in another.

The style matters too. An underwired bikini top can sit very differently from a bandeau or non-wired top, even when both are labelled with the same size. Plunge, full-cup and strapless styles can all fit the bust in slightly different ways.

The same applies across bikini tops, bikini bottoms and one-piece swimsuits.

If a particular product has its own size information, use that before relying on a general chart.

Is Your Bra Size the Same as Your Swimwear Size?

Sometimes, yes.

If the swimwear uses bra sizing, your usual well-fitted bra size is a sensible place to start. A 34F bikini top, for example, follows the same general band-and-cup sizing idea as a bra.

That doesn’t mean every 34F will fit exactly the same. Different brands and shapes can still feel slightly different.

Bikini bottoms are separate and won’t use your bra size. You’ll normally choose those using your waist, hip measurements or clothing size.

Why a Professional Swimwear Fitting Can Help

Supportive swimwear has a few more moving parts than a basic swimsuit, especially when cups and underwires are involved.

A professional Liza Clifford fitter can check things such as:

• Underband fit

• Cup coverage

• Breast positioning

• Underwire placement

• Strap adjustment

• Torso length

• Support requirements

• Styles that suit your shape and preferences

Sometimes the problem isn’t simply the size. A different cup shape, a longer torso or another style altogether may suit you better.

If you’re uncertain, book a Liza Clifford fitting or ask the team for help before ordering.

 

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FAQs

How do I know if I'm between swimwear sizes?

If you fall between two sizes look at the cut, fabric and brand of the swimwear - there isn't one solution that suits every swimsuit. For bikinis you've also got the option of mixing and matching different sizes for the top and bottom which often sorts the problem out pretty easily.

Should I Size Up or Down in Swimwear?

There isn’t one rule for whether you should size up or down in swimwear. The right size depends on your measurements, the style and how the garment is designed to fit.

A smaller size shouldn’t dig in, flatten the bust or cause breast tissue to spill from the cups. A larger size shouldn’t gape, shift around the body or feel too loose to provide proper support.

Rather than automatically sizing up or down, focus on how the swimwear fits and feels when you move.

Can My Bikini Top and Bottom Be Different Sizes?

Absolutely yes. Many women find that they do need different sizes on their top and bottom. The thing is, your bust, waist and hips just don't always fit neatly into one size category, which is why separates can be so useful. You can choose a top that fits your bust and then choose a bottom that fits around your waist and hips.

Is My Bra Size the Same as My Swimwear Size?

If you're buying swimwear that's designed to fit like a bra then using your correctly fitted bra size as a starting point is a good idea.

Just remember that even though the sizes are similar, fit can vary a bit between brands and styles, so check how the cups and band actually sit once you have the swimsuit on.

How Should an Underwired Swimsuit or Bikini Top Fit?

The band should feel firm around the body without being painful. Your breasts should sit fully inside the cups, and the underwire should follow around the breast tissue rather than resting on it.

The straps should feel secure too, but they shouldn’t be carrying all the support.

Why Does My One-Piece Swimsuit Pull at the Shoulders?

It could just be that the swimsuit is too small, but it can also be that the body of the swimsuit is just too short for you. If that's the case, it will naturally pull down on the straps and shoulders. So checking your torso measurement is a good place to start - that might tell you if you need to go up a size or if you just need to go for a different cut.

What Swimwear Size Should I Choose for a Fuller Bust?

If you've got a fuller bust, then looking for cup-sized swimwear is probably the way to go, rather than just going for the standard sizes. It'll give you a better fit, and save you a lot of hassle in the long run.

Start with your correctly fitted bra size and look for swimwear that gives you the level of support and coverage you need. If you're still unsure, get in touch with a professional swimwear fitter who can help you find both the right size & the right style for you.