What Is Sizing Like at Oseree?

Oseree fits true to size, but the cut runs deliberately slim and stops at XL (a UK 14), so if you're ever caught between two sizes or you carry a fuller bust or hip, size up. That's the short version. Now let me give you the proper stylist's breakdown, because Oseree is one of those Italian labels where knowing the quirks before you order saves you a returns-label headache and a sulk.

First, who are Oseree?

Oseree is a Milan-born luxury swimwear and resortwear house, beloved for its liquid-gold lurex, that signature metallic sheen, latex maillots and those barely-there sporty sets that have been all over Capri and the Amalfi coast for the last few summers. It's glamour with an Italian accent — and like a lot of Italian swimwear, it's cut for a long, lean silhouette. That's not a criticism, it's just the design language you're buying into, and it tells you everything about how to size.

How Oseree sizing actually works

Oseree uses letter sizing — S, M, L, XL — rather than UK dress numbers, which trips a lot of people up. Here's the honest read on it:

It runs to a slim grade. A size S roughly corresponds to a UK 8, M to a 10, L to a 12 and XL to a 14. The brand itself admits some styles come up small, so their own advice is to take the larger size if you're in between.
The size range is narrow. Oseree currently stops at XL. If you're above a UK 14, or you're an 8 on the bottom and a 12 on top, this is a brand where I'd measure properly first rather than guess.
The fit model is tall and slim. The pieces are styled on a long torso, so if you're petite or short in the body, the high-cut legs and low backs will sit higher and more revealing on you than on the model. Lovely if that's the look you want — worth knowing if it isn't.

Fabric changes everything here

This is the bit most size guides skip. Oseree's pieces don't all behave the same:

Latex and the structured maillots are the snuggest things in the range. They have very little give, they're meant to cling, and they can feel tight when you first pull them on. Take your truest size, or size up if you want a more relaxed feel.
The lurex and Lumière sheen fabrics have a touch more stretch and are far more forgiving — these are the ones I'd point a nervous first-time buyer towards.
The sporty bralette-and-brief sets are the most adaptable. A separates top and bottom means you can mix sizes if your proportions don't match a single number, which is gold for anyone who's pear or fuller-busted.

A few honest stylist confessions

I'll be straight with you, because I learned all of this the expensive way. My first Oseree piece was a gold lurex two-piece I ordered in my "usual" size for a trip to Puglia — and on me, with a bust that needs a bit more room, the top was a fraction too keen. Lesson one: with Oseree, go by your largest measurement, not your habitual label size.

The flip side — my favourite styling win — was a client of mine, a 34DD, who I steered straight into the sporty set rather than a one-piece. We took the top a size up and kept the bottoms true, and it was the first swimsuit she'd worn in years that she didn't tug at all day. That's the magic of separates and the moral of the whole post: don't be loyal to one number.

And the cautionary tale: a metallic piece I rinsed but left to dry scrunched up at the bottom of a beach bag came back slightly relaxed at the seams. These fabrics are gorgeous but they want a cold rinse and a flat dry, every time. Treat them well and the fit holds.

Where to shop if Oseree isn't quite your fit

Maybe you're outside the size range, maybe the price tag made you wince, or maybe you just want options. Here's where I'd send you instead, by budget — all chosen specifically because they do swimwear and resortwear genuinely well, not because they're the usual names.

High street

Marks & Spencer — the best high street swim for anyone needing real bust support; they do separate cup sizes and proper tummy control, which Oseree simply doesn't.
Boden — flattering prints, dependable underwiring and a size range from 4 to 24, so it picks up exactly where Oseree leaves off.
COS — sculptural, pared-back swimsuits that come closest to Oseree's clean Italian minimalism at a fraction of the price.
Mango — trend-led Mediterranean swim with metallics and cut-outs that nod to the Oseree look for holiday-budget money.
Seasalt Cornwall — coastal, sustainable and actually built to swim in, not just pose by the pool.
Hush — the place for the kaftans, sarongs and beach cover-ups that complete a resort wardrobe.
Monsoon — embellished, sun-ready beachwear if you like a bit of holiday drama.

Premium

Ganni — playful Scandinavian swim with a fashion-week edge; statement pieces that photograph beautifully.
Toteme — elevated, minimalist and quietly expensive-looking, for the woman who wants a black swimsuit that does all the talking.

Luxury & designer

Max Mara — polished resortwear and elegant swim with the kind of tailoring you'd expect from the house; the grown-up alternative.
Ralph Lauren — classic, timeless one-pieces and clean silhouettes that never date — the antidote to anything too trend-driven.

Two independents worth knowing

Davy J — a brilliant British-made label crafting durable swimwear from regenerated ocean nylon (including recovered fishing nets). Designed to genuinely survive a dive, with serious hold — ideal if you want substance under the style.
Stay Wild Swim — a London-based, eco-luxe brand making sleek, sculpted swimsuits from regenerated ocean plastic. Quietly cool, ethical, and very much in the Oseree spirit without the Oseree size limits.

Never squint at a size guide again

Oseree is exactly the sort of brand Tellar was built for — letter sizing, a slim grade and fabric quirks that a generic chart won't warn you about. Tellar is the UK's leading sizing tool: match your body once and we'll give you your exact size across 1,500+ brands, instantly.

Measure once — by bust, waist, hip, or an existing brand size you already know fits.
Use the Store Size Lookup to get your precise size in any brand — COS, Reiss, Everlane, Arket and more.
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Start here: tellar.co.uk