The easiest way is to begin is to select the size you usually wear. Our swimwear sizing and measurements are consistent with most swimwear brands. 

We always recommend sticking to your normal underwear size as most swimwear will fit using this rule (keeping in mind the Cup Size which is found in the product description). 

The body measurements outlined in the size guide below is to help you find your perfect Sea Level Swimsuit.

US (in) 4/XS 6/S 8/M 10/L 12/XL 14/XXL 16/3XL
42" 44"
Underbust  28" 29" 31" 33" 35" 37" 38"
Waist 25" 26" 28" 30" 32" 34" 36"
Hip 37" 38" 40" 42" 44" 46" 47"
D 34.5" 35" 37" 39" 41" 43" 45"
DD 35.5" 36" 38" 40" 42" 44" 46"
E/F 36.5" 37.5" 39.5" 41.5" 43.5" 45.5" 47"
AUS 8 10 12 14 16 18 20
Eur 34 36 38 40 42 44 46
UK 8 10 12 14 16 18 20
France 36 38 40 42 44 46 48

How to measure

Bust Measurements

As demonstrated in the picture above, make sure you have your tape under your arms and straight across your back and you have measured the largest size of your bust.

The underbust measurement is to be done at the point underneath your bust line and the circumference measured straight across the body (especially important for a Bikini Top).

Waist Measurement

Bend to one side to find the natural indentation in your torso, this is your natural waistline. Again, this measurement is to be done with a straight-line circumference. Run the tape measure around this point keeping tape parallel to the floor.

Hips Measurement

The hip measurement is the largest part of your body. This is not to be confused with where your hip line sits. If you find the largest part of your body, generally over your behind (often over your upper thighs and pelvis rather than over your hip bones), this will give you an accurate measurement.

Find your perfect fit! Here are our most common fit questions.



What is Multifit?

Multifit means this swimsuit fits a multitude of different sizes. Featuring a fixed foam cup that is sewn into our swimsuit, designed to fit a wide range of bust sizes. Our Multifit cup uses a special grade foam that is strong enough to have a mould that fits in our swimwear before wear yet flexible enough to conform to the bust of the wearer after. With further wear, you will feel the Multifit cup conform more to your size!

Will Multifit support my bust size?

No wiring is used in our multifit cup technology, creating a softer, more natural, and feminine appearance. These cups are specialised to fit across C-D/DD cup sizes, and in some cases up to E-EE busts. This generally comes down to breast tissue as well as the amount you want to flaunt!

Bust support


Underwire swimwear is all about providing women with the support they need when getting into the water. Our Underwire styles use firm, structured underwire that is sewn into the bra frame of your swimsuit.

Soft Foam Cups

There are two types of soft foam cup, classic and moulded. These cups are stitched into the swimwear and are non-removable, and are great for subtle shaping and smoothing.

Removable Cups

These are ideal for a larger bust, as you can remove cups to give more depth. You can opt to remove these cups and Powermesh lining.

Our styles with removable cups still provide support due to our Powermesh lining (think
similar to a sports bra!)


What is Powermesh Technology?

We want you to feel comfortable and supported! Our Powermesh stretches four ways which means it will mould to your body and your movements! It moulds to your body over time to accommodate the wearer with a ‘custom fit’ while also retaining its strong and supportive hold through a tightly woven fabrication. We use Powermesh to internally line our swimsuits on the front, back and sides, so all bases are covered. Its soft touch texture makes it feel smooth against the skin. Powermesh is compressive by nature which is why it helps to shape and enhance your body, while also allowing your skin to breathe! It’s one of our favourites!

Size & fit

What if I am in-between sizes?

This is highly up to personal preference. Some people may prefer a tighter fit to a looser fit and vice versa.

Our size chart is a flexible guide, and we offer a range of cup sizes from A to G.

If you are unsure of which size to get, please reach out to our fit specialists!

What if I have a long/short torso?

We’ve got you covered! For a short torso, we recommend styles with adjustable straps, and halter neck styles.

For long torsos, we also recommend styles with adjustable straps, halterneck styles, and pairing our singlet styles with any of our bottoms.

You can also size up for any of our Mulitfit or Moulded Cups styles, as they are designed to support a range of bust sizes.

What if I do not have measuring tape?

If you don’t have a measuring tape handy, measure the area with a piece of string and hold the marked spot up to a ruler).

What if it does not fit?

We offer a hassle-free returns policy! If you have swimsuit does not fit and you’ve found that you need another size, it’s a quick and simple process to find the right one. Head over to our returns page to simply exchange your size!

Caring for your swim

How can I care for my Sea Level Swim?

We have taken great pride in selecting the finest quality fabrics for our sustainable swimwear The most important thing you can do for prolonging the life of your swimwear is to launder it correctly.

Read more about how to care for your swimsuit here.

Do sunscreens affect my Sea Level Swim?

Sunscreens, body lotions, moisturisers, self-tanners, bronzers can all effect our swimsuits. The fabric used in our swimwear loves to hold onto oils and chemicals used in these substances. This eventually leaves permanent discolouration and damage to your swimsuit if not cared for correctly. Read more on our care guide here.


Is Sea Level Swim sustainable?

In 2022, 90 percent of our collections will be made from recycled base cloths – this takes in all designs from our essential main lines right through to our vibrant fashion prints.

To achieve a 100% recycled garment, our team is working towards incorporating recycled linings, performance mesh and trims. Our fabric technology is industry-leading: Swim Level collections are made using a revolutionary regenerated nylon filament yarn derived from pre-consumer waste.

Get in touch

If you need any more assistance, we are here to help!

Please email our customer service team at 
or start a chat with a fit specialist.