What Is Sizing Like at Thom Browne?

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

Thom Browne runs significantly smaller than standard UK sizing — we're talking roughly two full sizes down — and uses its own numerical size system (0 through 4) rather than conventional UK, EU, or US labels. If you've never bought Thom Browne before and you order based on your usual size, there is a very good chance it won't fit. This is not a label where you can guess. Trust me.

I've been a fan of Thom Browne's women's tailoring for years — the crisp suiting, the immaculate pleated skirts, those impossibly sharp blazers with the grosgrain stripe trim. There's genuinely nothing else quite like it. It's classic American Ivy League sportswear channelled through a very precise, very considered, very expensive lens. But the sizing? It's one of the most confusing in the designer market. I had a client come to me utterly baffled after ordering a size 2 blazer — which, on paper, should have been her size — only for it to arrive barely large enough to button across her ribcage. Once you understand the system, it all makes sense. But that understanding matters enormously before you spend four figures on a suit.

How Thom Browne's Size System Actually Works

Thom Browne uses a proprietary 0–4 sizing scale for womenswear. Crucially, these numbers do not correspond to standard dress sizes. The brand's silhouette philosophy — slim, tailored, body-skimming — means the cuts are deliberately close to the body with minimal ease built in. Here's the rough conversion to UK sizing:

Thom Browne SizeUK Size (approx)EU Size (approx)US Size (approx)Bust (cm)Waist (cm)Hips (cm)04–632–34080608616–834–36284649028–1036–384886894310–1238–406927298412–1440–4289676102

* These are approximations. Thom Browne's cuts run slim even within these numbers — always cross-reference your measurements with the specific product's size guide before ordering.

What this means in practice is that if you're a UK 10 in most brands, you'll likely be a Thom Browne size 2 or 3 depending on the garment — and you should always err on the side of the larger number if you're between sizes. The brand does not do generous. That's rather the point.

Garment by Garment: What to Expect

Blazers & Suiting: The most size-critical pieces in the collection. Thom Browne's signature cropped blazers are cut extremely close across the chest and shoulders. If you have broader shoulders or a fuller bust, size up without hesitation — there is no ease in these patterns and no forgiveness whatsoever. A blazer that won't close at the front is a very expensive mistake.
Pleated Skirts: The pleats give a little more room than the tailored pieces, but the waistbands are firm and precise. Go true to your Thom Browne size here, or size up one if your waist and hips are different proportions.
Dresses: Shift and sheath styles run very slim. Anything with a defined waist seam will need to fit both your waist and your bust — check both measurements carefully. The brand's more relaxed shirt-dress styles are marginally more forgiving.
Knitwear: A rare moment of relative generosity. The knit pieces tend to have a bit more give than the tailored items. True to Thom Browne size, or even down one if you prefer a cleaner, slimmer drape.
Trousers: Slim through the leg and cropped at the ankle — that's the Thom Browne signature. The waistband tends to run firm. Size up if you're at all unsure, particularly if you're fuller through the hips and thighs.
Outerwear: Coats and overcoats are slightly more accommodating than the suiting — they need to layer over it, after all. Still slim, but if you're between Thom Browne sizes, you may find you can stick to your usual number here.

My Practical Tips Before You Buy

Measure yourself properly first. Bust, waist, hips — all three. Thom Browne's sizing is precise enough that a centimetre or two genuinely matters in the tailored pieces.
Always size up if you're between sizes. There is no stretch in Thom Browne's suiting fabrics. When in doubt, go larger — a slightly looser blazer is always preferable to one you can't close.
Consider your body proportions. If you're narrow through the shoulders but fuller through the hips, or vice versa, you may find different sizes work for different garments. This is not unusual with precision tailoring — it's just the reality of buying a truly structured piece.
Buy from a retailer with a good returns policy. Net-a-Porter, Harrods, and the Thom Browne website itself all carry the collection. Given the price point, always buy somewhere you can return with ease if the fit isn't right.
Consider a tailor. If you fall between sizes and a piece is otherwise perfect, a good tailor can do a great deal with Thom Browne's clean construction lines. It's well worth factoring in the cost.

Where to Get the Thom Browne Look for Less

Thom Browne sits firmly at the top end of the designer market — a single blazer will typically set you back somewhere between £800 and £2,500. But the aesthetic — that sharp, preppy, clean-lined tailoring — is very much having a moment, and there are some brilliant brands doing it brilliantly at a fraction of the price.

High Street Picks

Cos — The closest you'll get to Thom Browne's restrained, architectural sensibility on the high street. Their tailoring is clean, their fabrics are decent, and the price is genuinely kind. Brilliant for the crisp white shirt and slim trouser combination that defines the TB look.
Massimo Dutti — Consistently excellent for grown-up tailoring with a European finish. Their blazers and trousers are well cut and hold their shape far better than the price suggests.
Jigsaw — A quietly brilliant British brand for considered tailoring and classic suiting separates. Their approach to colour and proportion is closer to Thom Browne than most people realise.
Tommy Hilfiger — For the preppy, Ivy League, red-white-and-blue stripe elements of the TB world, Tommy remains the most accessible point of entry. Their blazers and classic trousers are reliably well made.
Gant — Another brand rooted in East Coast American sportswear and classic tailoring. Their Oxford shirts, chinos, and structured blazers sit squarely in the same universe as Thom Browne, at a completely different price.
Reiss — For sharp, premium-feeling suiting that still falls in the accessible price bracket. Their tailored blazers and cigarette trousers are excellent quality and have a clean, precise cut that suits the TB fan down to the ground.
Whistles — Reliable for elevated, minimal suiting pieces with a British edge. Their tailored separates and blouses are understated in exactly the right way.

Premium Picks

Me&Em — Well made, grown-up, genuinely excellent tailoring. Their blazers and trousers are among the best at the premium price point and they understand proportion in a way that many brands don't.
LK Bennett — For classic, polished occasion suiting and the kind of structured pieces that hold their own in a boardroom or at a smart lunch. Their fabric quality is consistently strong.

Independent & Left-Field Picks

Margaret Howell — If you love Thom Browne but want something British, restrained, and quietly radical, Margaret Howell is your answer. She's been making beautifully considered tailoring and workwear in London for decades — clean lines, excellent fabric, zero trend-chasing. A genuinely essential brand that deserves far more attention than it gets.
Nili Lotan — A New York-based label beloved by stylists and largely unknown to the broader public. Nili Lotan does precision tailoring with a relaxed-luxury feel — impeccable trousers, beautiful shirts, structured outerwear — that sits in the same considered, quietly confident space as Thom Browne. Utterly worth bookmarking.

Get Your Exact Thom Browne Size — Use Tellar

Thom Browne's sizing system is one of the trickiest in fashion — and at these prices, guessing is not an option. This is exactly where Tellar.co.uk earns its keep. It's the UK's leading free sizing tool, covering 1,500+ brands so you can find your precise size before you spend a penny.

Here's how it works:

Measure once — enter your bust, waist, and hip measurements, or simply input a brand you already know fits you.
Use the Store Size Lookup tool to get your exact size across 1,500+ brands instantly — including Thom Browne, COS, Reiss, Arket, and many more.
Always free — no app, no subscription, no faff. Works directly in your browser.

And don't miss the Tellar Fashion Hub — an ever-growing library of honest, unsponsored posts from our stylists covering every fashion and sizing question you could possibly have. No ads. No sponsored content. Just straight, reliable advice.