What Is Sizing Like at St Agni?

St Agni generally runs true to size, but with a relaxed, intentional cut you need to understand before you buy. Tops and shirts lean boxy and oversized, trousers fit true through the waist with deliberately long legs, and the shoes run narrow — which is why the brand itself often nudges you to size up on footwear. Get those three quirks straight and you'll nail the fit first time.

I've styled enough quiet-luxury wardrobes to know that St Agni is the kind of label clients fall hard for and then panic over at checkout. It's an Australian house, so the sizing is built on an Australian/European framework that doesn't always map cleanly onto UK numbers. I learned that the slightly embarrassing way: my very first St Agni order, a linen blazer I'd been coveting for months, arrived swimming on me because I'd stuck to my usual UK size without checking how their cut actually behaves. Lesson learned — and now I check every time.

The Quick Answer, Category by Category

St Agni's silhouettes are relaxed but they vary a fair bit depending on the piece, so here's how it breaks down:

Tops & shirts: Often drop-shouldered, boxy and oversized, especially the organic cotton and linen styles. Stick to your usual size for that fluid, draped look, or size down if you want it closer to the body. The basic knit tanks and A-line linen blouses in particular run large.
Trousers: High-rise with elongated legs and frequently a hidden elastic back for a bit of give. The waist runs true, so prioritise your waist and hip measurement. If you're curvier or between sizes, size up to avoid pulling across the hips. Anyone under about 5'4" should budget for a quick hem.
Dresses: Minimalist slips and structured wraps. Linen shirt dresses run loose; wool knits sit closer to the body. Bias-cut styles hug more than the product shots suggest, and taller frames should double-check the length.
Shoes: Listed in European sizes and cut narrow. Most styles are true to length, but if you've a wider foot or you're eyeing a closed, woven or mule style, go up a half-to-full size.

My Styling Take

St Agni lives and dies by proportion. Because so much of the range is intentionally relaxed, the trick is to anchor the volume. When I style their boxy linen shirts, I'll tuck the front into a high-rise trouser so you keep the easy drape up top without losing your waist entirely. With the slip dresses, I size for the bust and shoulders first — that's where they can feel narrow — and let the length fall where it falls.

One genuine win from my own wardrobe: I sized down a half on a pair of their leather mules after reading the narrow-fit warnings, and they've moulded to my feet beautifully over two summers. The flip side of that fail-then-win story? Returns to Australia can be slow and pricey, so it's worth buying from a UK or EU stockist where you can, and getting the size right before it ships rather than after.

Where to Shop a Similar Look

If you love the St Agni aesthetic — clean lines, neutral palette, that quietly expensive feel — but want options across different budgets, here's where I'd send clients.

High Street

COS — The closest high-street match for St Agni's architectural minimalism. Sculptural shapes, oat-and-stone tones, brilliant for capsule basics.
Massimo Dutti — Elevated tailoring and genuinely good leather at a high-street price; their relaxed trousers and longline coats have that same understated polish.
Whistles — Contemporary, clean and grown-up, with relaxed shirting and slip dresses that sit nicely next to St Agni.
Jigsaw — Understated British quality, strong on neutral knitwear and trousers cut for real bodies.
Mango — Their committed minimalist edit punches well above its price for linen co-ords and tailored separates.
Uniqlo — Unbeatable for clean linen shirts and seasonless basics to layer underneath the statement pieces.
Me&Em — Elevated, considered tailoring with the kind of fabric-forward feel St Agni fans gravitate towards.
Hush — Relaxed, easy minimalism in soft neutrals; lovely for off-duty linen and jersey.

Premium

Toast — Natural fabrics, artisanal minimalism and a muted palette — arguably the most St Agni-spirited brand on this list.
Sézane — Parisian ease with beautiful linen and considered tailoring; a touch more romantic but the same quiet-luxury DNA.
Joseph — Refined, fluid tailoring and exceptional trousers — the go-to when you want the cut to do the talking.

Luxury / Designer

Totême — The Scandinavian quiet-luxury benchmark; if St Agni is your love language, Totême is the next step up.
By Malene Birger — Sculptural, neutral-led pieces with a slightly bolder hand for when you want the minimalism to feel directional.

Two Independents Worth Knowing

And because the best finds rarely sit on the front page, two genuinely independent labels I keep coming back to:

Deiji Studios — A small Australian linen specialist with the same relaxed, sun-bleached minimalism — wonderful for breathable separates and loungewear that earns its keep.
Esse Studios — Another Australian indie doing sharp, sculptural tailoring in a tight neutral palette; very much the considered, slow-fashion sister to St Agni.

Stop Guessing Your St Agni Size

St Agni's Australian-meets-European sizing is exactly the kind of thing that trips up UK shoppers, and ordering three sizes "to be safe" is no fun when returns ship back to Australia. That's the whole reason I co-founded Tellar.

Tellar is the UK's leading free sizing tool — match your body to 1,500+ brands instantly and never squint at a size guide again. Measure once using your bust, waist and hip, or simply tell us a brand size you already own, and we'll do the rest.

Measure once, using bust, waist, hip — or your existing size in a brand you already wear.
Use our Store Size Lookup to get your precise size in any brand — COS, Reiss, Everlane, Arket and more.
Always free, no downloads needed — it works straight in your browser.

There's also the Tellar Fashion Hub: a library stacked with free posts from our stylists. Honest, unbiased, independent and always free — style advice, top picks and the best brands, with no sponsored fluff.

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Written by Ella Blake, Senior Fashion Stylist & Founder of Tellar. Always honest, always unbiased, always free.