What Is Sizing Like at Marks & Spencer mens clothing?

The short answer: true to size, leaning generous

If you take one thing away, take this — M&S is cut for real, comfortable wear, not for the catwalk. Across most ranges it comes up true to size or very slightly generous, especially through the chest and waist. That's deliberate. Their core customer wants to sit down at a desk, drive a car and eat a Sunday roast without the seams complaining.

What I rate most, though, is the consistency. The thing that ruins online shopping is when a "medium" means three different things across three products. M&S keeps their blocks tight and predictable, which is exactly why I trust them for posting back-and-forth orders less often than almost anyone else.

Suits and tailoring: more fits than most realise

This is where M&S quietly punches above its price. The tailoring runs through five distinct fits, so you're not forced into one silhouette:

Skinny — closest to the body, narrow leg. Great if you're slim and under 30; less forgiving if you carry weight on the thigh.
Slim — the sweet spot for most men. Tapered but not painted on.
Tailored — a shaped waist and gentle taper without the squeeze. My default recommendation for weddings.
Regular — proper room through the chest and seat. Genuinely comfortable for long days.
Relaxed — the loosest, leaning into the softer modern shapes.

Crucially, the jackets come in Short, Regular, Long and Extra Long, adjusting body length by roughly 3.5cm a step. If you're 6'2"+ and have spent your life with jacket hems hovering above your seat, this matters enormously. The Big & Tall range is one of the best on the high street, full stop.

Stylist tip: Buy the jacket for your shoulders, not your stomach — shoulders can't be let out cheaply, waists can. If the shoulder seam sits clean on the edge of your shoulder, you've got the right size, even if the buttons feel a touch snug at first.

Shirts: know your four fits

M&S formal shirts are sized by collar in inches and come in four cuts, and getting these mixed up is the single most common sizing mistake I see:

Regular — the most generous, boxy through the body. Forgiving but can balloon if you're lean.
Tailored — narrower through chest and waist; the everyday choice for most.
Slim — back darts to pull in excess fabric. Sharp under a suit.
Skinny — the trimmest, smaller range.

Go by your actual neck measurement, then pick the fit by your body shape rather than your ego. A 16" collar in a Tailored fit beats a 15.5" in Slim that you can't fasten after lunch.

Trousers, chinos and jeans

Trousers are sized by waist x inside leg in inches, which is a blessing — no vanity sizing nonsense. Most chinos and formal trousers now carry a touch of stretch, so I'd stick to your honest waist measurement. The jeans tend to come up true; if you're between sizes and like them sitting on the hip, size down rather than up, because the stretch will give.

Knitwear and casual: where M&S genuinely shines

Their lambswool and merino knits are, pound for pound, some of the best value in Britain. Sizing here runs S to 5XL and comes up true to slightly generous, so if you like a closer fit under a jacket, take your normal size; if you want to layer a tee underneath, you've got room. The Autograph sub-line lifts the fabric quality noticeably, and M&S Sartorial is where the sharper formal pieces live.

How M&S compares — and where else to look

M&S occupies that comfortable, dependable middle ground beautifully. But sizing is personal, and if their cut isn't yours, here's where I send clients depending on the silhouette they're after:

High street alternatives

COS — for a more architectural, relaxed, fashion-forward cut. Sizes generous, so often worth dropping one.
Reiss — slimmer and more European through the body than M&S; brilliant tailoring if you're lean and want a sharper line.
Arket — Scandinavian, slightly oversized basics with lovely fabrics; true to size but roomier than M&S equivalents.

Independent & boutique labels

Universal Works — Nottingham-based, workwear-inflected, relaxed and a little arty. Sizing is generous and unstructured.
Percival — playful London brand doing characterful shirts and knits; true to size with a modern, slightly trim cut.
Oliver Spencer — soft tailoring and beautiful fabrics for the man who wants a jacket that feels like a cardigan.

Designer & luxury

Paul Smith — British wit with a slim, precise cut. Run trim through the chest, so size up if you're broad.
Sunspel — the gold standard for tees and polos; understated, true to size, made to last decades.
Officine Générale — Parisian, soft-shouldered tailoring with an effortless drape; sizing leans slim.

The honest takeaway? M&S gives you 80% of what those pricier labels offer at a fraction of the cost — but the fabric, the finish and the sharpness of cut are where you feel the gap as you climb the tiers.

What to buy now, and how to wear it

A navy Tailored-fit suit — the single most useful thing in any man's wardrobe. Wear the jacket with chinos midweek, full suit for occasions.
An overshirt or chore jacket — the workwear-leaning shape is firmly on trend and bridges smart-casual effortlessly.
A merino crew in a muted tone — olive, oatmeal or rust. Layer over a collared shirt, sleeves pushed up.
Pleated, slightly wider trousers — the skinny era is over; a touch of room reads modern and is far more flattering.

Stop guessing your M&S size — match your body in seconds

Here's the bit that saves you the returns hassle entirely. Tellar is the UK's leading sizing tool — your body, matched exactly to 1,500+ brands instantly. Never squint at a size guide again.

Measure once using your bust, waist, 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 more.
Shop with confidence — no guesswork, fewer returns, better-fitting purchases.
Always free, no downloads — it works right in your browser.

And once you've nailed your fit, the Tellar Fashion Hub is a full library of free posts from our stylists. Honest, unbiased, independent and always free — style advice, top picks and the best brands, with no sponsorship pulling the strings.

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