Sizing & Fit

Find Your Perfect Fit

Our swimwear fits A to J bust — the key is your measurements, not your cup size. Enter your bust, underbust and waist and we'll find your size in seconds.

Measurement-based sizing
A to J bust friendly
Free fit consultation
Easy exchanges

Your measurements,
not your cup size.

Our swimwear is designed to fit A through to J bust. Rather than sizing by cup, we size by bust, underbust and waist — because every body is different. Enter your measurements and we'll recommend the right size for your shape and fit preference.

B U W
B
Bust
Measure around the fullest part of your chest, keeping the tape parallel to the floor.
U
Underbust
Measure directly under your bust, around your ribcage. This helps us understand your bust-to-underbust ratio.
W
Waist
Measure around the narrowest part of your torso, usually 2–3 cm above your belly button.
It Will Feel Firm
Our Italian fabric is compressive by design. It softens and moulds to your shape after the first wear in water.
Size to Your Bust
If your bust and waist put you in different sizes, always size to your bust. Our wrap styles accommodate the difference.
Between Sizes?
Size up. The fabric will hold you beautifully without being restrictive once it's softened.
Still Unsure?
Send your measurements to our fit team and they'll personally advise you. Contact us →
Find My Size
3 quick questions — get your personalised size recommendation
1
Measurements
2
Fit Preference
3
Category
Your Measurements
Bust Fullest part of chest
cm
Underbust Directly under your bust
cm
Waist Narrowest part of torso
cm
How Do You Prefer Your Swimwear to Fit?
🎯
True to Size
Firm, supportive hold. Sculpts and shapes as designed.
🌊
Slightly Relaxed
A little more room. Less compression.
💪
Fuller Bust
Larger bust relative to waist. We'll prioritise bust fit.
🤔
Not Sure
We'll recommend based on your measurements.
What Are You Shopping For?
👙
Bikinis
Tops, bottoms, sets. AU 4–26 · US 0–22.
🌸
Wrapsuits
One-piece wrap styles. Same sizing as bikinis.
🌴
Resortwear
Kaftans, dresses, cover-ups. XS–XXXL.
✨
Everything
Show me my size across all categories.
Your Recommended Size
AU 14
US 10
Bust
—
Underbust
—
Waist
—
Shop AU 14 / US 10

Swimwear & Wrapsuits

AU 4–26 · US 0–22 · Measure over bare skin

Baiia Size Bust Waist Hips
Fuller Bust?
If your bust measurement puts you in a larger size than your waist, size to your bust measurement. Our wrap styles are adjustable and will accommodate the difference beautifully.
It Will Feel Firm at First
Our Italian compressive fabric is designed to feel snug. This is intentional. It softens and stretches to your shape after the first wear and with water.
Between Sizes?
If you're on the border between two sizes, size up. The fabric will hold you in beautifully without being restrictive once it's softened.

Resortwear & Cover-Ups

XS–XXXL sizing · Relaxed fit · Order your usual size

XSUS 0–2
SUS 2–4
MUS 4–6
LUS 8–10
XLUS 10–12
XXLUS 14–16
XXXLUS 18–22

Resortwear is designed with a relaxed fit. Order your usual size. The Cecile Kaftan and multiway dresses fit multiple sizes — see individual product pages for specific guidance.

Not Sure of Your Size?
Use our interactive fit finder — enter your measurements and we'll recommend the perfect size for your shape and fit preference.
Talk to a Fit Expert
Send us your measurements and receive a personalised recommendation within 24 hours. A real person reviews every request.
Contact Our Fit Team
Customer Review
"The fit team helped me choose between sizes — they were completely right. Best swimwear I've ever owned."
Sarah M. · Verified Buyer

See exactly how it fits before you buy.

We believe in radical transparency about fit. Watch our model put on the swimwear — you'll see how it stretches, how the wrap ties work, and how it looks on a real body. No filters, no tricks.

It will feel firm. Our Italian compressive fabric is designed to sculpt and support. This is not a defect — it's the feature.
Water transforms it. After your first swim, the fabric softens and moulds to your shape. Most customers say it feels completely different after one wear.
It gets better with time. The more you wear it, the more it becomes yours. The fabric remembers your shape.
If it's still too firm after water, size up. We offer easy exchanges. Our fit experts can help.

Fit by Style

Complimentary Service
Talk to a Baiia Fit Expert
Not sure about your size? Send us your measurements and our fit team will personally recommend the right size for your body and the style you're shopping for. A real person reviews every request — we'll be in touch within 24 hours.
Contact Our Fit Team →
"I consulted with the fit team before ordering and they were so helpful — they recommended I size up based on my measurements and they were completely right. Perfect fit."
Sarah M. · Verified Buyer · Size 14
What our fit service includes
Personalised Size Recommendation
Send your bust, underbust, waist and hips using the form above and we'll reply within 24 hours with a recommendation specific to your body and the style you're considering.
Style-Specific Advice
Tell us which style you're considering and we'll advise on whether that particular cut runs true to size, small, or large — and how to style it for your shape.
Easy Exchanges
If the fit isn't perfect after your first wear, we offer easy exchanges. Our fit experts can help you find the right size before you even need to exchange.
International Sizing Help
Confused by AU vs US vs EU sizing? Just send us your measurements and we'll cut through the confusion with a direct recommendation.