What Is Sizing Like at Primark? A Menswear Stylist's Honest Guide

The honest truth: Primark sizing is inconsistent

Primark runs several different ranges — basics, slim-fit, "essentials", loungewear, tailoring — and they don't all speak the same language. A medium in one range fits like a large in another. It's the price you pay for fast fashion at that price point: the fabric, the factory and the pattern all shift season to season. Once you accept that, you shop smarter. Here's how each category actually behaves.

Tops, tees and jumpers

Basics and essentials run true to size, often a touch generous. If you're a solid medium elsewhere, a Primark basic medium will usually sit right, sometimes a hair roomy in the body.
Slim-fit and "muscle fit" lines run small. Size up one from your usual. I learned this the hard way when a slim-fit polo tried to strangle me at a summer BBQ.
Oversized and relaxed lines run big by design — brilliant for the boxy, heavyweight look that's everywhere right now, but don't buy your normal size expecting a regular fit.

Shirts

Casual shirts use alpha sizing (S–XXL) and tend to be cut slim through the chest. Big lads, size up or go for the regular-fit range specifically.
Formal shirts use collar sizes (roughly 14.5"–17.5") and are fairly reliable to the neck measurement — it's the body cut that varies, so check whether it's slim or regular before you commit.

Trousers, jeans and chinos

Waist sizes run in inches and are true-to-slightly-generous. A little vanity sizing creeps in, so your "32" might feel a smidge kinder than at a premium brand.
The leg length is the real problem. Primark trousers frequently come up long. My first-ever Primark chinos pooled around my ankles like I'd borrowed my dad's. Buy the shorter leg length or budget for a turn-up.
Joggers and cargos are generous and forgiving — genuinely some of the best value in the shop.

Tailoring and shoes

Suits use standard chest sizing (36–46) and the jackets are cut slim. If you're between sizes or muscular, go up. The trousers follow your waist, not the jacket chest.
Shoes run slightly small and narrow. Half-sizes are rare, so if you're a 9.5 or have wider feet, take the 10.

How to actually shop Primark well

Primark's superpower is that it's in-store — you can try before you buy, which quietly solves half the sizing problem. Use it. A few rules I stick to:

Always try both your size and one up. With this much variation, guessing is a fool's errand.
Check the actual fabric weight. The cheap thin cotton pills fast; the heavyweight tees and brushed-back joggers are where the value genuinely lives.
Buy the trend, not the staple. This is the shop to test a colour, a cargo, a boxy tee — not the £4 white shirt you'll wear to death. For things you wear constantly, spend a little more elsewhere.
Ignore the label range name and judge the garment in your hand. Fit varies more than the tag admits.

Where I'd look for the pieces Primark can't nail

Primark is fantastic for trying things cheaply, but for the items you'll live in, here's where I send clients across every budget.

High street — better basics that last

Uniqlo — the gold standard for consistent sizing and fabric that survives the wash. Their Supima cotton tees and AIRism layers are the grown-up version of a Primark basic, and a medium is a medium every single time.
Marks & Spencer — unbeatable for shirts, knitwear and tailoring with a proper size range and reliable fits. If Primark's collar sizing let you down, M&S won't.

Independent & boutique — character and honest fits

Community Clothing — Blackburn-made, transparent, ethical, and the chinos and tees are cut true with no nonsense. A brilliant antidote to fast-fashion guesswork.
Percival — a London label doing characterful knits and shirts with a considered, modern fit. Perfect when you want something nobody else in the room is wearing.

Designer & luxury — buy once, wear for years

Sunspel — the definitive elevated British tee and polo. If a Primark heavyweight tee is your gateway, this is the destination.
Paul Smith — proper British tailoring with a sense of humour and colour. The cut is refined but wearable, and the sizing is beautifully consistent.
A.P.C. — for raw denim that ages to your body. The polar opposite of disposable jeans, and worth every penny.

My honest take: build the bones of your wardrobe from Uniqlo, M&S and a couple of quality investment pieces, then use Primark to play — to test trends and colours before you commit real money. That's how you get the best of both worlds without a drawer full of things that don't fit.

Stop guessing your size — let Tellar do it for you

Here's the thing about sizing being all over the place: you don't have to memorise which range runs small or squint at a size guide ever again. Tellar is the UK's leading real-time sizing tool — your body matched exactly to 1,500+ brands in seconds. It's completely free, works in your browser, and there's nothing to download.

Measure once — using your bust, waist and hip, or just your existing size in a brand you already own.
Use the Store Size Lookup to get your precise size in any brand — COS, Reiss, Everlane, Arket and hundreds more.
Shop with confidence — no guesswork, fewer returns, better-fitting buys.
Always free — no downloads, works straight in your browser.

Find Your Size — Store Size Lookup How to Measure (Men)

And it's not just the tool. The Tellar Fashion Hub is a growing library of free posts from our top stylists — style advice, top picks and best brands, all in one place. Honest. Unbiased. Independent. Always free.

Primark will always have a place in a well-dressed bloke's wardrobe — you just have to shop it with your eyes open and your tape measure handy. Try before you buy, judge each piece on its own merits, and save your serious money for the staples. Do that, and you'll walk out with genuine wins and not a single regret.

More free menswear guides from the Tellar Fashion Hub:Menswear: The Secret to Smart-Casual Comfort Best Men's Jeans Brands: High Street, Premium & Designer How to Do Casual Style Well: Menswear Brands & Styling Tips