Which Brands Run Small and Which Run Large? A Stylist's Honest Guide

Tellar Fashion Hub | Sizing Guides | By the Tellar Style Team

Because life is too short for a wardrobe full of returns.

Some fashion brands run small, some run large, and some are a complete lottery — and knowing which is which before you buy will save you an enormous amount of frustration. I've spent years dressing women of every shape and size, and if I had a pound for every time a client called me in a panic from a changing room convinced she'd "gone up a size," I'd be retired in the South of France. She hadn't gone up a size. She'd bought from Zara. Let me break it all down for you.

Brands That Run Small — Always Size Up

These are the ones where you genuinely need to go up one size, sometimes two. The cut is narrow, the proportions are European, and they do not account for the fact that most real women have hips.

Zara — Notoriously small, especially across the bust and hips. I always tell clients to go up a size as a starting point, then try from there. Their denim in particular runs very slim through the thigh.
Mango — Very similar to Zara in its sizing philosophy. Slim, sleek European cuts that leave little room for curves. Size up on everything, particularly blazers and tailoring.
COS — Architectural shapes and minimal fits. The sizing is precise, which means there's no extra room built in. If you're between sizes, go up.
Arket — Scandinavian sizing that runs narrow through the shoulders and bust. Lovely quality but be prepared to size up, especially in knitwear.
Anthropologie — Wildly inconsistent depending on the brand within the brand, but the Anthropologie own-label tends to run small. Always check the individual garment guide.
Whistles — Beautiful brand, but their fitted styles particularly come up small. The blazers and shift dresses are the worst offenders.
Reiss — Tailored and precise. I love Reiss for suiting and occasionwear, but the sizing is slim. If you have a fuller bust or hip, go up one.

Brands That Run Large — Consider Sizing Down

These are the lovely surprise brands — the ones where you pull on your usual size and find it's actually roomy, or where sizing down gives you a much more flattering fit.

M&S — Marks & Spencer has always been generous with its sizing, particularly in knitwear, jersey, and tailoring. If you're between sizes here, go down — you'll be glad you did.
Next — Their dresses and trousers in particular come up roomy. A brilliant brand for curvier figures because of this generosity, but do try before you buy if shape and fit matters to you.
Boden — One of the most reliable quality brands on the high street, but the sizing is definitely on the generous side, particularly in jersey pieces and casual wear.
Fat Face — Very relaxed fits across the board. Size down if you want anything close to the body — otherwise embrace the relaxed look, which is rather the point with Fat Face.
White Stuff — Another brand with a relaxed, lived-in sizing. Their dresses and tops especially come up large. Brilliant for layering and casual dressing.
Me&Em — Slightly more generous than you might expect from a premium brand. Worth checking their size guide carefully, but many women find they're a size down from their usual here.

The Completely Unpredictable Ones

These brands will keep you on your toes. Different categories, different ranges, sometimes even different seasons — all size differently. Never assume.

H&M — Their bottoms run genuinely small whilst their knitwear can come up enormous. You could be a 12 in their jumpers and a 14 in their jeans. It's a puzzle I've never quite solved.
ASOS — Their own label is inconsistent, though it tends to lean small. The issue here is that ASOS carries hundreds of brands, each with their own sizing logic. Always read the individual reviews — they're genuinely useful.
Phase Eight — Varies enormously by garment type. Their occasionwear tends to be true to size, but their casual pieces can come up small. Their size guides are actually quite reliable so do use them.
Mint Velvet — A brand I adore for its effortless style, but its sizing shifts between collections. Generally true to size in their knitwear, slightly small in fitted dresses.

Luxury and Designer Sizing: A World of Its Own

Designer sizing deserves its own conversation entirely. As a general rule, European luxury brands — think French and Italian houses — run small and narrow. British designers tend to be more generous. Here are a few key names to know:

Max Mara — Italian sizing, so it runs slim. Their coats in particular come up narrow through the shoulders. Size up for anything structured.
Claudie Pierlot — French brand, French sizing. Which means it's small, chic, and designed for a very particular silhouette. Always go up a size.
Hobbs — British through and through, and the sizing reflects that. More generous than European equivalents, good for curvier figures, excellent in occasionwear.
LK Bennett — True to size for the most part, though their shoes run slightly narrow. Consistent enough that once you know your size here, you're sorted.

Two Independent Brands Worth Knowing

I always want to shine a light on smaller, independent brands beyond the high street giants — and these two are brilliant for honest, inclusive sizing:

Kitri — A London-based independent brand beloved by fashion editors. Their sizing is true to size and they include detailed garment measurements, which is hugely helpful. Excellent quality for the price point.
Albaray — A considered, sustainable brand with refreshingly clear sizing notes on each product page. They run true to size and their customer reviews back this up consistently.

My Top Stylist Tips for Getting It Right First Time

Ignore the number on the label entirely — it means nothing across different brands.
Always read customer reviews, particularly if they mention fit — these are more valuable than any size guide.
If buying online from a brand new to you, start with one piece and check the returns policy before buying a whole outfit.
Measure yourself properly — bust, waist, and hips — and compare these to the brand's specific garment measurements rather than generic size charts.
And honestly? Use a proper sizing tool. It is the single biggest time-saver I've found for my clients.

Never Guess Your Size Again — Use Tellar

This is exactly the problem that Tellar.co.uk was built to solve. It's the UK's leading sizing tool — free, browser-based, and genuinely brilliant. You measure yourself once (bust, waist, hip — or simply enter a size you already know fits in one brand) and Tellar instantly matches your body to the correct size across 1,500+ brands. No more guessing, no more returns, no more standing in a changing room questioning your entire existence.

Their Store Size Lookup tool gives you your precise size in specific brands — whether that's COS, Reiss, Arket, Zara, or any of the other 1,500+ brands in their database. It takes seconds and it works seamlessly in your browser. No app download, no subscription, no faff.

The Tellar Fashion Hub is also worth bookmarking — it's a library of free, honest, independent style guides written by real stylists. Always unbiased. Always free. Think of it as your personal stylist on call.

Useful Tellar guides on sizing and style:

The Ultimate Clothing Sizing Guide — everything you need to know about how sizing works across brands
Jeans Trends 2026 — the best styles and exactly where to shop them
Ultimate Guide to Dresses & Best Buys
Ultimate Guide to Jackets & Best Buys

Find Your Size in 1,500+ Brands →

The bottom line is this: sizing inconsistency is one of fashion's most persistent and frankly most annoying problems — but it doesn't have to be yours. Know your brands, trust your measurements over labels, and let tools like Tellar do the heavy lifting. Happy shopping.