Style guide
The 2026 swimwear fit guide
Six shapes, one honest rule: buy for the body you have on holiday, not the one you plan to have. Here is how we help customers find their match.
By the My Store studio
7 min read
Every summer we get the same message: "I love it, but will it actually fit me?"
It is the fairest question in fashion. Swimwear is the one thing we buy with the least amount of fabric and the most amount of doubt. So instead of another trend list, we asked our buying team to write down what they check before a single piece makes it into the store — cup structure, stretch percentage, how a side tie behaves after an hour in salt water.
What follows is that checklist, in plain language. Read it once and you will know within thirty seconds whether a swimsuit on a screen is going to work on you.
01 — The principle
Start with the shape, not the size
Sizing on swimwear is the least reliable number on the label. Two size mediums cut from different patterns can sit five centimetres apart on the hip. What does travel across brands is structure: where the fabric gathers, how high the leg is cut, whether the bust is supported by an underwire or by stretch alone.
So we shop the shape first. Ruching down the centre front softens the midsection because the eye follows the vertical line. A halter neck pulls the shoulders back and lifts a fuller bust. A boyshort leg gives coverage without shortening the leg the way a straight-cut leg does. Pick the structure that answers your one insecurity, then worry about the number.
02 — The edit
Three shapes that flatter almost everyone
Hand-picked from this season's arrivals, each one chosen for a different concern: coverage at the waist, support at the bust, and a leg line that lengthens.
"If a swimsuit needs you to hold your breath, it is the wrong swimsuit. We would rather send you a second size than have a piece sit in your cupboard."
Our buying team
03 — The detail
Why the fabric decides the fit
Read the composition before the reviews. The blend we look for is roughly 80% polyamide to 20% elastane: enough elastane to hold its shape wet, enough polyamide to stop the fabric going sheer when it stretches over the hip. Anything below about 15% elastane will bag at the seat by the second swim.
Lining matters just as much. A fully lined front panel is what gives a light colour its opacity and a ruched panel its smoothing effect — without it, ruching just looks like creasing. And a removable cup should sit in a stitched pocket, not float freely, or it folds in the wash.
- Stretch test: pull the fabric — if you can see your hand through it, size up or skip it.
- Strap check: adjustable or halter straps beat fixed shoulder straps for a longer torso.
- Care: rinse in cold water the same day — chlorine and sunscreen break elastane faster than wear does.
04 — Around it
The layers that travel with it
A swimsuit only works as hard as what you pack around it: something soft for the room, something to keep documents dry, something that dresses the whole thing up for dinner.
05 — Answers
Fit questions, answered
I am between two sizes — up or down?
Size up for one-pieces and underwired styles, where length through the torso and cup volume are fixed. Stay at your smaller size for tie-side bottoms and tankinis, which adjust as you wear them.
Which shape works for a fuller bust?
Look for an underwire, a halter neck, or both. A halter distributes weight across the neck and shoulders rather than the straps, and a removable cup lets you fine-tune the shape.
Will a light print show more?
A busy print actually breaks up the silhouette, so it draws less attention than a pale solid. If you want the most forgiving option, pair a printed bottom with a dark ruched top.
How do I keep it looking new?
Cold rinse after every wear, dry flat in the shade, never wring it out, and skip the tumble dryer entirely. Rotate two pieces on a long trip so each one fully dries between swims.
MS
Written by
The My Store studio
We hand-pick every piece we sell and answer fit questions personally. Not sure about a size? Message us before you order — quality you deserve, service that cares.
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