How to Find Your Perfect Fit & size at Alyx

By Ella Blake | Tellar Fashion Hub

Alyx — or to give it its full name, 1017 ALYX 9SM — runs small, runs European, and absolutely does not accommodate a generous approach to sizing. If you've ever ordered a piece from Matthew M. Williams' label and found yourself wrestling with a zip or swimming in excess fabric, you're far from alone. Getting your size right at Alyx is genuinely one of the trickier exercises in luxury fashion — but once you crack it, the pieces are extraordinary.

"Alyx is one of those brands where a centimetre either way can be the difference between sculptural and impossible. Measure properly, and the reward is worth every bit of the effort."

What Is Alyx, and Who Is It For?

Founded in 2015 by designer Matthew M. Williams, Alyx sits firmly in the luxury streetwear space — think technical outerwear, sleek black everything, those iconic roller-coaster buckles, and pieces that blur the line between fashion and armour. It's not a brand for the faint-hearted, and neither is its sizing. Alyx designs for a lean, angular silhouette; it's heavily influenced by Italian construction and Parisian minimalism, which translates into cuts that are intentionally close to the body.

I'll be honest — I discovered this the hard way when I picked up an Alyx jacket in what I assumed was my usual size. It wasn't even close to doing up across the chest. Lesson firmly learned.

How Does Alyx Sizing Run?

The short answer: small. The slightly longer answer: small and inconsistent depending on the category. Here's how I'd break it down:

Outerwear and jackets — these are the most unforgiving pieces in the range. Alyx cuts are narrow across the shoulder and tight through the body. Size up at least one, possibly two, if you have any width across the back or bust.
Knitwear and sweatshirts — slightly more relaxed, but still lean. True to size if you like a close fit; size up for anything more comfortable.
Trousers — cut for a slim, straight leg with minimal ease. If you have any curve through the hip or thigh, go up one size. The waist tends to run small too.
T-shirts and tops — these vary enormously. Some styles are boxy and generous; others are cropped and narrow. Always check the specific product measurements rather than relying on your standard size.
Unisex pieces — Alyx produces a significant amount of gender-neutral styles, which typically run on men's sizing. Women shopping these should generally drop two sizes from their usual women's size (i.e., if you're a UK women's 12, start at a men's XS).

How to Measure Yourself for Alyx

This is non-negotiable with a brand like this. You cannot guess your way into Alyx — the margins are too tight and the price point too high to risk it.

Bust / chest: Measure at the fullest point, tape parallel to the floor. This is your most critical measurement for Alyx outerwear.
Waist: Natural waist, an inch or so above the navel. Essential for trousers and structured tops.
Hips: Fullest point, roughly 8 inches below the waist. Key for trousers and skirts.
Shoulders: Measure straight across the back from shoulder point to shoulder point. Alyx shoulders are precise — this measurement can save you an expensive mistake.
Sleeve length: Worth measuring if you're shorter or taller than average, as Alyx doesn't typically offer length variations.

Once you have your measurements, cross-reference them against Alyx's size chart on their website — they do provide one, and it's worth the extra five minutes.

Alyx's Aesthetic: How to Style It

Part of getting Alyx right is understanding what the brand is doing aesthetically. It's dark, it's architectural, it's built around the idea of utilitarian luxury. The pieces aren't designed to be worn casually — even when they look effortless, there's intention behind every layer.

Pair a structured Alyx jacket with wide-leg tailored trousers for a high-fashion silhouette that balances the jacket's narrow cut.
Their mesh and technical tops work brilliantly under blazers — a nod to the brand's layering philosophy.
The buckle hardware is a styling statement on its own; keep everything else clean and minimal around it.
Footwear matters enormously at this level. Alyx pieces live happily alongside clean white trainers or sharp ankle boots — nothing too decorative.

Where Else to Shop the Aesthetic at Every Budget

I love Alyx, but I'm also a pragmatist — not every wardrobe has room for luxury investment prices across every piece. Here's how I'd build the look at different price points:

COS — the closest high street match to Alyx's minimalist, structural DNA. Their tailored trousers and technical outerwear are genuinely excellent and the quality-to-price ratio is hard to beat. Sizing at COS is true to European, similar to Alyx, so apply the same sizing-up logic.
All Saints — brilliant for the darker, edgier pieces that complement an Alyx wardrobe. Their leather and faux-leather jackets punch above their weight. Tends to run slightly smaller than UK standard — check their size guide.
Zara — when they get it right, they really get it. Their structured outerwear and wide-leg trousers can fill a genuine gap without the Alyx price tag. Sizing is inconsistent across ranges; always read reviews per item.
Massimo Dutti — for cleaner, more refined workwear-adjacent pieces to pair with statement Alyx outerwear. Their sizing is consistent and reliable; runs true to European standard.
Reiss — polished tailoring and outerwear that holds its own alongside luxury pieces. Tends to run true to UK sizing, occasionally a touch small across the shoulder.
Mango — a surprisingly strong option for dark, directional pieces on a mid-range budget. Their leather-effect trousers in particular are a recurring favourite. Sizing runs slightly small; go up if in doubt.
Urban Outfitters — for the more relaxed, streetwear-adjacent pieces that sit naturally alongside Alyx's aesthetic. Sizing varies significantly by brand stocked; always check individual listings.

For independent alternatives in this space, two brands genuinely worth knowing are Rains — a Danish label doing exceptional technical outerwear with a cult following among the fashion crowd, available in the UK and sizing true to European standard — and Feng Chen Wang, a London-based designer whose deconstructed tailoring and layered aesthetic sits beautifully in conversation with Alyx without the same price point. Both are the kind of finds that make a wardrobe feel genuinely considered rather than assembled.

My Honest Verdict on Shopping Alyx

Alyx is not a brand you can shop impulsively. It rewards patience, proper preparation, and a willingness to return things if the fit isn't right first time. But when it works — when the jacket fits across the shoulders and the buckle sits exactly where it should — there really is nothing quite like it. The pieces are conversation-starters; they're the kind of things people ask you about.

Size up. Measure your shoulders. Check the product-specific measurements rather than trusting the label. And if you're buying unisex, go in expecting to size down significantly from your usual women's sizing. Do those three things, and Alyx will reward you handsomely.

Stop Guessing Your Size — Let Tellar Do It For You

Sizing at a brand like Alyx is exactly where Tellar.co.uk earns its place in your bookmarks. It's the UK's leading free clothing sizing tool — you enter your measurements once, and it instantly matches you to the right size across 1,500+ brands. No subscriptions, no faff, completely free. For a brand as precision-cut as Alyx, having your exact measurements to hand before you buy isn't just helpful — it's essential.

Here's how Tellar works:

Measure once — input your bust, waist, hips, or an existing brand size you know fits well.
Use the Store Size Lookup tool — get your precise recommended size for Alyx, COS, Reiss, All Saints, Zara and over 1,500 more brands, in seconds.
Always free — works instantly in-browser, no account required.

The Tellar Fashion Hub is also packed with honest, independent style guides written by real stylists — no ads, no sponsors, no agenda. A few worth bookmarking:

Tellar is completely independent — no brand pays to be featured, no sponsored results, just accurate sizing information matched to your body. At the price point Alyx operates at, shopping with that kind of certainty isn't a luxury. It's just good sense.