What Is Sizing Like at Kiko Kostadinov? A Stylist's Honest Guide

By Ella Blake – Fashion Stylist | Tellar Fashion Hub – Always honest, unbiased & unsponsored

Kiko Kostadinov sizes small and runs narrow, and crucially, it uses French sizing — not UK sizing — which catches a lot of shoppers completely off guard. If you've been staring at a size tag that says "36" and wondering why it fits more like a UK 8, that's your answer. This is a London-based label with a very deliberately avant-garde sizing philosophy, and knowing how it works before you buy could save you a very expensive return.

First, Who Is Kiko Kostadinov?

If you don't already know the brand, here's the quick version: Bulgarian-born, London-based designer Kiko Kostadinov graduated from Central Saint Martins in 2016, won the British Fashion Council's prestigious NEWGEN prize, and almost immediately became a cult name in the kind of fashion circles that use the word "utilitarian" as a compliment. He launched the menswear label first, became Creative Director at Mackintosh, and did a covetable collaboration with ASICS that practically broke the internet. In 2018, he partnered with twin sisters Laura and Deanna Fanning — fellow CSM graduates — to launch the womenswear line, which has been operating with its own distinct identity ever since.

The womenswear is the Fanning sisters' vision: unconventional pattern cutting, off-beat fabric pairings, sculptural silhouettes, wide-leg trousers in two-tone panelled constructions, satin blazers with unexpected cut-outs. It's not for the faint-hearted, and neither, frankly, is the sizing. This is a designer brand made for a very specific body — and you need to understand that going in.

The French Sizing System Explained

This is the most important thing to understand about Kiko Kostadinov, and it's the bit that trips everyone up. The brand uses French (FR) sizing, not UK sizing. The two systems are not the same, and assuming they are is a mistake I've seen people make repeatedly — myself included, the first time I came across a Kiko piece on a resale platform labelled "38" and assumed it would fit like a UK 38 chest. It does not.

Here's your quick conversion guide:

French Size (FR)UK Size (approx.)EU Size (approx.)US Size (approx.)FR 34UK 6EU 34US 2FR 36UK 8EU 36US 4FR 38UK 10EU 38US 6FR 40UK 12EU 40US 8FR 42UK 14EU 42US 10

Most Kiko Kostadinov womenswear is produced in sizes FR34 to FR42, though in practice the range skews towards the smaller end. Products stocked by retailers like SSENSE, Farfetch and H.Lorenzo typically show models wearing FR36 — that's a UK 8 — with measurements around a 32" bust, 25" waist, and 35" hip. These are slim, precise measurements, and the pieces are cut accordingly.

Does Kiko Kostadinov Run True to Size?

Within the French sizing system, the brand is broadly consistent — but the silhouettes vary dramatically depending on the piece. That's actually one of the most interesting things about the womenswear line: a draped satin midi dress might be described as "relaxed fit" and feel generous in the body, while a structured blazer or tailored trouser is precision-cut with very little ease. You genuinely cannot assume one garment will behave like another.

Here's how sizing breaks down by category:

Trousers: The brand's wide-leg, panelled trousers are a hero piece — but they're cut for a narrow hip and a high waist. Proportionally, the waistband is fitted; the leg flares out below. If you're wider in the hip or have a bigger seat, size up and have the waist taken in. The quality of construction makes it worth it.
Blazers and structured outerwear: Cut narrow across the shoulders and chest. Stick true to your French size and expect a close, structured fit. These are not boxy or oversized — they're architectural and fitted.
Draped tops and dresses: More relaxed through the body, with generous draping and cut-out details. These tend to work across a slightly wider range of sizes than the tailored pieces. That said, the brand still skews small — if you're between sizes, go up.
Knitwear: When Kiko does knits, they tend to be fitted and close to the body. Don't rely on stretch to rescue a size down here.
Footwear (ASICS collaborations etc.): The collaborative footwear with ASICS has its own sizing quirks — users widely report that the fit runs slightly narrow, and sizing up half a size is common advice.

Who Does Kiko Kostadinov Womenswear Actually Suit?

I'll be honest with you — this is not a brand designed for every body, and I think pretending otherwise would be doing you a disservice. The silhouettes are conceived for a lean, narrow frame. That doesn't mean you can't wear it if you're not, but it does mean you'll need to work harder with sizing, and some pieces simply won't translate to a curvier figure without alteration.

Where it works brilliantly:

Slim to straight figures: The precision-cut tailoring and wide-leg trousers are absolutely made for you. The proportions are designed with this silhouette in mind.
Petite to average height: The high-waisted cuts and dramatic leg shapes can actually work very well on a shorter frame — they elongate brilliantly.
Those who love a statement drape: If you're drawn to sculptural, deconstructed fashion, the Fanning sisters' draped satin pieces are genuinely extraordinary, and a bit more forgiving in fit than the tailoring.

Where to be careful:

Curvy or hourglass figures: The fitted waistbands and narrow hip allowances in the trousers can be a real issue. I'd always recommend sizing up in bottoms and having the waist adjusted if needed.
Broad shoulders: The blazer cuts run narrow across the back. Check shoulder measurements carefully before buying.

A Personal Note on Buying Kiko Kostadinov

The first time I encountered a Kiko Kostadinov dress on a resale site, I was absolutely mesmerised by it — a draped satin piece in a warm amber, with these extraordinary folded sleeves. I bought it in what I thought was my size. Reader, it was not. I'd misread the French sizing conversion and ordered a full size too small. The shoulder draping couldn't happen because it had nowhere to go. I sold it on at a loss and swore I'd never make that mistake again. I haven't. But I genuinely think half the confusion around this brand comes down to that one issue — the French sizing — and once you've got that nailed, the rest is much more manageable.

If You Love the Aesthetic — What Else to Shop

Whether the price point isn't quite there yet or you just want more options in the same visual universe, here's where I'd point you — across every budget.

High street picks for a Kiko-inspired wardrobe:

COS — The closest thing on the high street to Kiko's design philosophy. Architectural cuts, unconventional proportions, minimal colour palette. Sizing is consistent and leans slightly generous. Brilliant for wide-leg trousers and structured blazers.
Zara — Has leaned heavily into the wide-leg, panelled trouser trend that Kiko helped popularise. Worth checking for statement pieces each season. Sizing can vary by piece — check the measurements.
Mango — Consistently strong for draped satin tops and wide-leg separates at a fraction of the price. Sizing runs fairly true to a standard European scale.
Urban Outfitters — A surprisingly strong destination for experimental, directional pieces. Good for cut-out tops, asymmetric hemlines and the kind of textural oddities Kiko fans gravitate towards.
Anthropologie — Excellent for the more textural, eclectic side of the Kiko aesthetic. Interesting fabric combinations and unusual print work that feels genuinely creative rather than trend-chasing.
All Saints — For the darker, more structured end of the Kiko spectrum. Good quality leather and heavy-fabric pieces with an edgier sensibility. Sizing tends to run true to a UK scale.
Claudie Pierlot — French brand with that same Parisian design precision. Interesting cuts, excellent tailoring, and a consistent, reliable sizing system. Great premium alternative at a lower price point than Kiko.

Premium alternatives:

Ganni — The Danish brand that shares a lot of Kiko's cool-girl, fashion-forward audience. More print-led, slightly more accessible in fit. A brilliant next-step brand for Kiko fans.
Nanushka — Sculptural, sustainable, and thoughtfully cut. The vegan leather pieces in particular have a very similar design sensibility to the Kiko blazer range.
A.W.A.K.E. Mode — London-based, unconventional cuts, interesting use of structure. Priced below Kiko but with genuine design credibility.

Luxury and designer alternatives:

Acne Studios — The Swedish label that shares Kiko's commitment to considered construction and unusual proportions. Sizing also uses EU/FR scale, so a similar approach applies.
Marni — Possibly the closest spiritual cousin to Kiko in the luxury space: eccentric, deliberately off-beat, beautifully made. Also runs small across most categories.
Issey Miyake — If you love the sculptural, draped quality of Kiko womenswear, Issey Miyake's Pleats Please line is an absolute revelation, and far more inclusive in its sizing.

Two independent picks you might not know yet:

Paloma Wool — A Spanish independent label with a genuinely devoted following. Eclectic knits, draped silhouettes, and an irreverent attitude to proportion that feels very aligned with the Kiko womenswear world. Sizing is generally one-size or S/M/L — and they're honest about who each piece fits.
Birgitte Herskind — A Copenhagen-based independent designer producing sculptural, architectural women's pieces with a strong silhouette focus. Not widely known in the UK yet, but absolutely worth the discovery.

Stop Guessing Your Size in Kiko Kostadinov

French sizing, narrow cuts, silhouettes that vary wildly by garment — Kiko Kostadinov is genuinely one of the trickier brands to size yourself for, especially online. And at these price points, getting it wrong is costly.

That's exactly what Tellar.co.uk is built for. It's the UK's leading free sizing tool — matching your exact body measurements to over 1,500 brands instantly, so you always know your right size before you buy.

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