Forget your dress size – measure instead!

Swimwear doesn't fit like standard street clothes or everyday bras. Grab a measuring tape and check two quick numbers:

Underbust

Measure snugly directly under your bust, right around your ribcage. This gives you your true band size.

Overbust

Measure around the fullest part of your chest. This tells you your cup volume.

Now the confusing part. Sizing labels aren't universal, so the same cup can wear a different letter depending on where the suit was made. In Australia, fuller cups usually run C to E. In the US, those same cups get labelled C to DDD (or F). 

At Sheila, our supportive styles carry both, so you'll see something like C–E AU / C–DDD US on the tag and know exactly where you land.

One more thing worth knowing: swim fabric relaxes a bit when it gets wet. If you're between sizes and want a snug, locked-in fit, size down. If you want an easier fit with a bit of room, size up.

Details to check before you buy

When you're shopping online, look closely at the product details for these four signs of good support:

A wide bottom band

The band around your ribs should do the supportive work, not your shoulder straps. If the straps are doing all the work, your neck and shoulders will ache within an hour.

Built-in cups or a shelf bra

Thin, single-layer fabric just squashes you flat. Look for moulded foam cups or an internal shelf bra that shapes and lifts, even when wet.

Curved seams

Flat side seams pull your bust out toward your armpits. Curved vertical seams give your chest room and shape it naturally.

Double-lined fabric

Cheap fabric stretches out fast in salt water and sun. Quality, double-lined recycled nylon stays snug and keeps its shape year after year.

Don't forget the sun protection!

When you’re spending hours by the water, support isn’t the only priority. Your décolletage is one of the most sun-exposed areas on your body, especially in lower-cut swim tops.

High-neck styles and UPF 50+ swim layers offer extra coverage from UV rays without getting in the way of your swim. That’s why every Sheila piece is crafted from UPF 50+ fabric, so sun protection is built right into the suit.

Frequently Asked Questions

What is the difference between a shelf bra and molded cups?

A shelf bra is an internal, supportive fabric band sewn into the lining (often housing removable pads) to provide gentle compression. Molded cups are shaped foam cups sewn directly in to hold a rounded profile without underwire. Both provide shape and security without stiff metal hardware.

Do I need a racerback if I have a fuller bust

Not for casual lounging, but it makes a noticeable difference for active water sports. Racerback and crossback styles pull strap weight toward the centre of your back, taking tension off your neck and shoulders.

What cup range does Sheila cover?

Our supportive swim tops and one-pieces are designed with fuller busts in mind, generally fitting cup sizes B through E (AU), or B through DDD/F (US). Check individual product pages for specific style recommendations.

Is a supportive swimsuit automatically less flattering or overly sporty?

Not when it is designed with considered patternmaking. Thoughtful elements like curved vertical seams, scoop and square necklines, and waist definition lift and sculpt your natural shape without compressing you into an unyielding block.