Reviewed by Baku's design and fit team

If you've ever stood in a change room adjusting straps, tugging at a leg line or wondering why the "right" size still doesn't feel right, you're not alone.

Finding the right swimwear isn't about dressing for a particular body shape. It's about finding the right support, cup fit and coverage for you.

The best swimsuit should stay comfortably in place, support you where you want it and give you the coverage you feel most comfortable wearing.

This guide draws on decades of Baku pattern-making and swimwear experience to help you understand how swimwear should fit, from choosing your cup size and bikini top to comparing bottom coverage, tummy control and the construction features that can make all the difference.

Consider this your complete swimsuit sizing guide — one to come back to whenever you're looking for your next bikini or one piece.

Start With What You Want From Your Swimwear

Rather than asking "What swimsuit suits my body shape?", start by asking what you want your swimwear to do.

I want more bust support

Start with your cup size, then look for features such as underwire, wider adjustable straps, supportive bands, longline shapes and internal support.

For fuller busts, shop your cup size rather than simply sizing up in a standard bikini top.

I want more coverage through the tummy

Explore Tummy Control styles and high-waisted bottoms.

Tummy control panels, powermesh and carefully placed ruching can provide additional support and a smooth, secure fit.

I want more bottom coverage

Your bikini bottom should be chosen according to the amount of coverage you feel comfortable wearing.

Explore Mid-Full Coverage, Regular and Boyleg styles for different levels of coverage.

I prefer a softer, less structured fit

Try triangle tops, bralettes and adjustable tie-back styles.

I want lift or added shape through the bust

A Booster top can provide extra lift and shaping, while moulded cups and underwire can create a more structured silhouette.

Shopped by Body Shape Before?

You might have searched for "pear", "apple", "hourglass" or "athletic" swimwear in the past. Those labels were only ever shorthand for support and coverage — and that's how we actually fit you:

• Curvier through the hips (what magazines called "pear") → High Waisted or Mid-Full Coverage bottoms, with any top in your cup size
• Softer through the middle ("apple") → One Pieces with Tummy Control, or High Waisted bottoms
• Fuller bust → let your cup do the work — shop your exact cup from A to G, or Fuller Cup D+
• Straighter frame ("athletic") → texture, ring details and Booster tops add shape where you want it
• Curvy top and bottom ("hourglass") → when the cup is right, most styles are yours

Whatever the label, the right fit comes from your cup size and the coverage you're comfortable in — which is exactly what this guide is for.

Why Swimwear Fit Is Different From Everyday Clothing

Swimwear asks more of a garment than almost anything else in your wardrobe.

It has to move with you, support you and hold its shape when wet — all while using far less fabric than most everyday clothing.

That's why finding your swimwear fit goes beyond knowing your dress size.

One of the biggest differences is that bikini tops and bottoms are sized independently.

Your bikini top should be chosen according to your bust and cup fit, while your bottom is determined by your waist, hip measurements and preferred coverage.

It's completely normal to wear a different size on top and bottom. Mixing and matching separates isn't a workaround — it's one of the best ways to achieve a more personalised fit.

How Should Swimwear Fit?

Regardless of the style you choose, there are a few signs that you've found the right fit.

It should stay put. You shouldn't need to continually adjust your bikini bottoms or check that your top has shifted after swimming. Elastic edges should sit comfortably against the skin and straps should stay in position.

There should be no gaping or pinching. Gaping around the cup, leg or waistband can mean the piece is too large or isn't the right shape for you. Spillage, digging or excessive indentation can indicate that you need more room.

Support should come from the swimsuit's construction — not from wearing it excessively tight. Features such as underwire, powermesh, boning, supportive bands and adjustable straps should be doing the work.

You should be able to move freely. Raise your arms, sit down, bend forward and move around. Your swimsuit should move with you without constantly riding up or sliding down.

If you're spending more time adjusting your swimwear than enjoying wearing it, try another size or style.

Bikini Top Fit Guide: Start With Your Cup Size

The amount and type of support you need from a bikini top can change significantly depending on your cup size.

That's why it's much more useful to shop according to your cup and preferred support than according to a traditional body-shape category.

A–C Cup

A–C cup fits offer plenty of flexibility depending on how much lift, structure or coverage you prefer.

Consider:

• Booster bras with moulded underwire cups and removable booster pads for additional lift and shape.

• Soft cup bralettes with contouring removable cups for a relaxed, modern look.

• Slide triangle tops with a tie neck and tie back, which let you personalise the fit to your exact proportions.

• Bandeau tops with gripper tape and side boning to keep the top anchored without straps, if you prefer that silhouette.

C–DD Cup

As the bust increases, coverage and structured support become more important without sacrificing style. Look for:

• C–D longline soft cup bras, which offer coverage and lift without underwire — a good option if you find underwire uncomfortable but still want structure.

• Booster balconette bras with underwire and either moulded or removable cups.
• D/DD moulded bras with soft moulded underwire cups and wider straps for extra weight distribution.
• Halter bras with a tie neck and back, which are particularly good for D/DD busts needing extra coverage.

D–E Cup

This is where underwire and reinforced construction genuinely change how a top performs. At this cup range, look for:

• D/E underwire bras with power cup support, hidden wire, and powermesh lining for shape that holds all day.

• D/E underwire singlets, which use ruching or a trapeze fit to add coverage through the tummy as well as the bust.

• D/E underwire one pieces with adjustable, convertible straps for contouring and shaping through the whole torso.

E–G Cup

Fuller busts need maximum support built into the garment itself, so it isn't relying on straps or tightness to hold everything in place. Key styles include:

• E/F ladder lace one pieces, which frame the bust while powermesh through the tummy adds control.

• F cup triangle bras with underwire and a customisable ruched centre front.

• E/F/G lace-up bras and one pieces, which use powermesh bust support and thick, adjustable straps for full coverage and maximum support.

If your top has underwire, it should sit securely beneath your bust without digging in or riding up.

Visible spillage around the top or sides of the cup can indicate that you need a larger cup or a different shape. If the cup puckers or gaps, you may need a smaller cup or another style.

The band should feel secure around your ribcage without being uncomfortably tight. Remember: your band provides an important part of your support.

Bikini Bottom Fit Guide: Choose Your Coverage

Your bikini bottom isn't determined by your body "type". It's about how much coverage you want and where you like your swimwear to sit.

Because Baku bikini tops and bottoms can be mixed and matched, you can choose the bottom cut you feel most comfortable wearing.

Boyleg

Boyleg styles offer fuller coverage through the bottom and sit lower around the leg.

They can be a practical choice if you prefer more coverage or want a secure style for active beach and pool days.

Brazilian

Brazilian bottoms offer minimal coverage through the back for those who prefer a more revealing silhouette.

Rio tie side. A rio-cut bottom with thin, adjustable tie sides. The tie feature means you can fine-tune the fit at the hip in a way a fixed-side bottom can't — loosen it for comfort, tighten it for a higher leg line.

Rio. A skimpier cut with a higher leg line and soft front edging. This style shows more leg than boyleg or Brazilian and suits anyone who wants a more elongating silhouette through the hip and thigh.

A high-waisted swim bottom -sits higher on the waist, typically at or around the natural waistline, providing more coverage through the stomach and hips. It creates a flattering, supportive silhouette while offering a comfortable and secure fit.

A regular swim pant sits comfortably on the hips with a classic mid-rise fit, offering moderate coverage through the front and back for an easy, flattering everyday swimwear shape.

How should bikini bottoms fit?

Whichever coverage you choose, the fabric should sit close to the skin without digging in.

The waistband shouldn't roll or continually move, while the leg opening should feel secure without leaving uncomfortable marks.

If you're constantly pulling your bottoms back into position, try another size or coverage style.

How to Measure Yourself for Swimwear

Getting an accurate measurement is the single most useful thing you can do before shopping, especially online. Here's how to do it properly:

Bust measurement. Wear a well-fitting, non-padded bra. Wrap a soft measuring tape around the fullest part of your bust, keeping the tape level and snug but not tight. This number, along with your band measurement, determines your cup size.

Band/underbust measurement. Measure directly underneath your bust, where an underwire would sit, keeping the tape snug and level all the way around.

Waist measurement. Measure around the narrowest part of your natural waistline — usually just above your belly button — without pulling the tape tight.

Hip measurement. Measure around the fullest part of your hips and bottom, standing with your feet together.

Take all measurements in your underwear or activewear, standing naturally rather than sucking in or straightening up more than usual — you want the number that reflects how your body actually sits day to day, not a best-case version of it.

Swimwear Support Features Explained

Sometimes two swimsuits in exactly the same size can feel completely different. That's because construction matters just as much as size.

Adjustable and Convertible Straps

Allow you to customise the length and positioning of your straps for comfort and support.

Underwire

Sits beneath the bust to provide structure, lift and separation.

Side Boning

Adds additional structure around the sides of the bust and can help keep the top securely positioned.

Powermesh

A supportive internal fabric often used through the bust or tummy to provide additional support.

Tummy Control Panels

Built into selected swimsuits to provide additional support and smoothing through the tummy.

Ruching

Gathered fabric adds texture and can provide additional coverage through particular areas of a swimsuit.

Removable Cups

Allow you to choose between additional shaping or a softer, more natural fit.

Booster Pads

Provide additional lift and volume through the bust.

Tie Backs

Allow you to customise the band fit. This can be particularly useful if you need more room through the cup but a smaller underbust fit.

Common Swimwear Fit Mistakes

Buying from your dress size alone

Your everyday clothing size doesn't tell the whole story when it comes to swimwear. Use your measurements and cup size as your starting point.

Assuming your bikini top and bottom need to be the same size

They don't. Choose each piece independently according to how it fits.

Sizing down for more support

Smaller doesn't necessarily mean more supportive.

A correctly fitted swimsuit with the right internal construction will generally provide better support than a swimsuit that's simply too tight.

Ignoring your band fit

Particularly for fuller busts, support doesn't come from the straps alone. A secure band and correctly fitted cup work together to support the bust.

Choosing a style based only on how it looks

Think about what you'll actually be doing in your swimwear. A style for relaxing beside the pool may have different requirements from one you're planning to swim, paddleboard or spend an active beach day in.

Frequently Asked Swimwear Fit Questions

Should swimwear fit tight or loose?

Neither. It should fit close to the body and stay securely in place without digging in, pinching or leaving uncomfortable marks.

How should a swimsuit fit around the leg?

The leg opening should sit against the skin without digging in and shouldn't continually ride up as you walk or sit.

What if my bikini top and bottom are different sizes?

That's completely normal. Choose your bikini top based on your bust and cup fit and your bottom according to your hip measurement and preferred coverage.

How do I know if my bikini cup is too small?

Spillage around the top or sides, an underwire that doesn't sit correctly beneath the bust or a centre front that pulls away from the body can all indicate that you need more room in the cup.

How do I know if my bikini cup is too big?

Excess fabric, puckering or gaping through the cup can indicate that the cup is too large or that the shape isn't right for you.

Is a triangle or underwire bikini better?

Neither is inherently better. A triangle provides a softer, more flexible fit, while underwire offers greater structure. Choose according to your cup size, preferred support and how you want your bikini to feel.

Are high-waisted bikini bottoms more supportive?

They provide additional coverage through the stomach, and selected styles may also include tummy-control construction for additional support.

Find the Swimwear Fit That Works for You

Finding your perfect swimsuit isn't about deciding whether you're a pear, apple, hourglass or any other shape.

It's about knowing your cup size, deciding how much support you want and choosing the coverage that makes you feel most comfortable.

Once you understand those three things, swimwear shopping becomes much simpler.

Start with your measurements, choose a top designed for your cup, select the bottom coverage you prefer and look for the construction features that provide the support you need.

Then choose the colour, print and style you actually love.

👉 Explore Baku Swimwear, Bikini Tops, One Pieces, A–C Cup, D+ Cup, E–G Cup, Tummy Control and Swim Bottoms to find your fit.