What Is Sizing Like at Saint Laurent Clothing?

Honest, unbiased and completely unsponsored — just real fit advice from someone who has dressed a lot of people in a lot of YSL.

Here's the short answer: Saint Laurent runs small and slim, cut to French and Italian luxury proportions that sit noticeably narrower than UK high street sizing — so for most tailored pieces, especially blazers, dresses and trousers, you'll want to size up at least one size. It's a brand built around a sharp, sculpted silhouette rather than comfort and stretch, and once you understand that, the sizing stops being intimidating and starts making sense.

I've styled Saint Laurent for editorial shoots, red-carpet fittings and private clients who saved for a single piece for a year — and the fit conversation comes up every single time. So let me save you the returns drama and walk you through exactly how it fits, garment by garment.

The Quick Verdict on Saint Laurent Sizing

Tailoring (blazers, suiting): Runs small and very slim — size up.
Dresses: Cut close, especially through bust and waist — size up if you're curvier.
Trousers & jeans: Skinny and high-waisted — go up if between sizes.
Knitwear & silk: Little to no stretch — measure, don't guess.
Outerwear: Closest to true to size, but check sleeve length.
Shoes: Style-dependent — pumps run small, sneakers true to size.

Understanding Saint Laurent's French Sizing

The first thing that trips people up is the numbers. Saint Laurent uses French and Italian sizing, so you'll see 34, 36, 38, 40 rather than a UK 8, 10, 12. As a rough guide, a French 36 lands around a UK 8, a 38 around a UK 10, and a 40 around a UK 12 — but and this is the important bit, those conversions are a starting point, not gospel. The cut is so trim that the number on the label rarely tells the whole story.

Stylist tip: Saint Laurent's proportions shift slightly season to season and even between factories, so never assume one size carries across the whole collection. The number that fit your blazer beautifully might be a touch tight in a dress from the same drop.

How Saint Laurent Fits, Piece by Piece

Blazers & Tailoring

This is where Saint Laurent earns its reputation. The Le Smoking tuxedo jacket and the classic wool blazers are deliberately razor-sharp through the shoulder and arm — gorgeous on, but unforgiving if you're caught between sizes. If you want to layer anything underneath, or you simply prefer a shoulder that doesn't pin your arms, size up. I learned this the hard way: I once let a client talk me into her "usual" size for a smoking jacket and the second she lifted her arm at the event, the whole line strained. Lesson logged.

Dresses

From slip dresses to structured mini and evening pieces, Saint Laurent dresses are cut to skim a slim frame. Bust and waist are the measurements that matter most here — if you carry more there, go up a size rather than fighting the zip. Satin and silk styles have zero give, so your body measurements, not your usual size, should make the call.

Trousers & Jeans

Think skinny, cigarette and high-waisted — sculpted and lean by design. They run small, particularly across the hip and thigh, so if you're between sizes or want any room to move, take the larger one. Non-stretch fabrics and zipped ankles are the usual culprits for a too-tight fit.

Knitwear & Silk Tops

Fine knits and silk blouses are designed for a clean, close line rather than a relaxed drape. There's minimal stretch, so check the measurements properly — a piece that looks fluid on the model is often more fitted than you'd expect in real life.

Outerwear

Coats, bombers and the cult Teddy jacket are the most forgiving category — typically true to size with a luxury, structured finish. The one thing to watch is sleeve length, which can run long on the more dramatic styles. If you plan to layer knitwear underneath, nudging up a size keeps the shoulder clean.

Shoes

Footwear is the one area where there's no single rule. The pumps — the Janis and Jamie styles especially — tend to run slightly small and snug at the toe, so half a size up is the safe move. The iconic Tribute and LouLou sandals fit narrow, so size up if you've got a wider foot. The Court Classic sneakers, by contrast, are reliably true to size. Patent leather is always the least forgiving, so factor that in.

Stylist tip: Saint Laurent shoes are exquisite but built for dinners and events, not all-day marathons. Buy them for the moment, not the school run.

Should You Size Up in Saint Laurent?

For the vast majority of pieces, yes — at least one size in clothing, half a size in most shoes. The only real exceptions are outerwear (true to size) and Court Classic trainers (true to size). When in doubt, the safest approach with a brand this slim and this expensive is to work from your actual measurements rather than the label you usually reach for.

The Best Alternatives to Saint Laurent

Saint Laurent is a serious investment, and not every piece needs that price tag to deliver the Parisian, rock-tailored look. Here's where I'd send clients chasing that same sharp, slightly undone elegance — across every budget.

On the High Street

Mango — brilliant for sharp blazers and slim tailoring with a real Continental edge.
Massimo Dutti — elevated suiting and leather that punches well above its price.
COS — minimalist, architectural lines for the cleaner end of the Saint Laurent look.
Reiss — polished tailoring and tuxedo dressing done properly.
& Other Stories — Parisian-leaning pieces with a softer, romantic finish.
Whistles — understated, grown-up cuts that nail occasion dressing.
Zara — the place for of-the-moment statement tailoring on a budget.
AllSaints — the high street's home of rock-chic leather and lean silhouettes.

Premium & Contemporary

Sandro — French, sharp and made for exactly this aesthetic.
Maje — playful Parisian tailoring with that effortless YSL attitude.
The Kooples — moody, rock-edged dressing with serious tailoring credentials.
Anine Bing — relaxed Scandi-LA cool that nods straight at the Saint Laurent blazer.

Luxury Peers

Celine — the closest spiritual sibling for slim, Parisian minimalism.
Khaite — modern tailoring and leather with the same quiet power.
Toteme — pared-back, beautifully cut staples for the understated set.

Independent Labels Worth Knowing

Sézane — the Parisian independent that built a cult following on effortless French-girl tailoring, beautiful blazers and that lived-in elegance — at a fraction of designer prices.
Rouje — Jeanne Damas's label, possibly the most authentically Parisian wardrobe going: slip dresses, sharp little jackets and proper rock-chic charm.

Both of those independents give you the Saint Laurent feeling — that nonchalant, slightly-rebellious French polish — without the four-figure outlay, and supporting them feels good too.

TELLAR FASHION HUB

Find Your Perfect Size in 1,500+ Brands

The UK's leading clothing size tool. Measure once, match to over 1,500 brands instantly — including Saint Laurent, Celine, Sandro, Mango and every label on the high street. Always free. Always honest. Always unsponsored.

Measure once — bust, waist, hip, or existing brand size
Get your precise size in any brand, instantly
Works in-browser — no downloads or sign-ups needed
Completely free, always

Visit Tellar.co.uk Try the Store Size Lookup Tool

The Tellar Store Size Lookup tool matches your body measurements to the exact sizing of each brand in our database — so whether you're investing in a Saint Laurent blazer or browsing the high street, you can shop with total confidence. No more guesswork. No more disappointing returns.

And if you're after more honest fashion advice, the Tellar Fashion Hub is packed with free posts covering everything from brand sizing guides to seasonal wardrobe edits — all written by our stylists, completely unsponsored, and always free to read.