What Is Sizing Like at Nike menswear?

Nike apparel generally comes up true to size on the label but athletic in the cut. That means if you take a medium in most British high-street brands, a Nike medium will usually be your number — but it'll hug the chest, shoulders and arms more than you might expect. Nike builds clothes to move on a body that's moving, so the default silhouette is trim. If you like a bit of air around you, or you're carrying any muscle up top, size up one and you'll be golden.

A couple of things worth knowing before you check out:

• Go by your chest, not your waist. If your chest and waist point to two different sizes on Nike's chart, take the size your chest tells you. It's the harder measurement to fudge.

• The line matters more than the size. Performance gear (Dri-FIT, Pro base layers) is deliberately snug. Sportswear (Club Fleece, Tech Fleece) is roomier and slouchier. Same "M" on the label, very different fit on the body.

• Between sizes? Size up for casual, stay put for the gym. A relaxed hoodie wants the extra room; a training top wants to stay close so it doesn't flap about.

Trainers: true to length, but on the narrow side

Here's where people trip up. Nike trainers used to be famous for running small, but these days most models come up true to length and simply a touch narrow. If you've got a wider foot, that's the bit to watch — length is rarely the problem, width is. The catch is that Nike prices in model-by-model quirks, so a blanket "go up half a size" rule will let you down. My cheat sheet:

• Air Force 1: runs about half a size large. Nearly everyone sizes down a half for a clean fit.

• Dunks: broadly true to size, though some retro colourways come up a little narrow.

• Pegasus & road runners: true to size, and — handily — offered in Wide fittings if you need the room.

• Flyknit uppers: that knitted sock-like build hugs the foot, so they suit medium-to-narrow feet best. Wide-footers, be cautious.

• Metcons (training): a wider, flatter toebox by design — great if the rest of Nike's range pinches you.

• Jordan: lines up with standard Nike sizing, but the '90s retros can feel a shade narrower.

How I'd style it, and what's landing right now

The move in 2026 is Nike worn grown-up — less head-to-toe technical kit, more single hero pieces folded into real clothes. A charcoal Tech Fleece half-zip under a wool overcoat with straight trousers and a pair of low-profile runners is quietly one of the best smart-casual looks going. On the leisure end, the oversized trend has fully arrived: a boxy Club Fleece hoodie sized up, worn with slim or tapered joggers so you're not swamped top and bottom. Balance is everything — if the top's roomy, keep the leg clean, and vice versa. And please, retire the all-white running shoe as a default; a muted grey, bone or washed-navy trainer reads far more considered with everyday clothes.

The brands I'd hang next to your Nike

Nike is the anchor, not the whole wardrobe. These are the eight I reach for most when I'm building out a client's sportswear and athleisure rail — each one with a note on how it fits relative to Nike, so you're not guessing.

HIGH STREET

adidas

The obvious rival, and for good reason. Sizing sits right alongside Nike — take your Nike size and you'll be close — but adidas apparel runs a hair more relaxed through the body, and the trainers (Samba, Gazelle, Ultraboost) tend to give you a touch more toebox room. If Nike's cut feels a size too keen, adidas is the easy sideways step.

Gymshark

British, gym-born, and cut for it. Gymshark's "muscle fit" pieces run noticeably slimmer than Nike — brilliant if you actually train and want the taper, but size up if you want a T-shirt you can breathe in outside the weights room. Superb value for training staples.

INDEPENDENT & BOUTIQUE

On

The Swiss brand that's everywhere now, and rightly so. The apparel is a tailored athletic cut, very close to Nike's slim performance lines. On the footwear, watch the snug models — the Cloud 5 and 6 have a tight entry and a tapered toe, so I'd go up half a size from your Nike; the Cloudmonster and Cloudrunner sit true. Genuinely lovely to run and walk in.

Castore

A British performance label that's grown up fast. The fit is athletic and close, a lot like Nike's Pro range, with lovely fabric weight and a cleaner, less logo-heavy look. If you want technical kit that doesn't shout, this is your rail.

Vuori

The antidote to all that compression. Vuori is soft, relaxed and roomier than Nike — the Ponto and Sunday joggers are the comfiest thing I own — so take your usual size and enjoy the ease. Perfect for the days that blur between the sofa and a coffee run.

DESIGNER & LUXURY

Stone Island

Where sportswear meets serious craft. Italian sizing means it comes up slimmer and shorter than Nike, so most men take a size up — a Nike L is often a Stone Island XL. Buy it for the garment-dyed sweats and the technical outerwear; nothing anchors a casual look with more quiet authority.

Y-3

Yohji Yamamoto's collaboration with adidas, and a totally different philosophy of fit. Expect oversized, draped, deliberately loose — the opposite of Nike's athletic trim — so size down if you don't want it billowing. The trainers run a little large too. This is sportswear as design object.

Moncler

The luxury end of technical outerwear. Moncler is cut trim and true to Italian sizing, so if you're layering over a hoodie, size up for room. Yes, it's an investment — but a Moncler shell over your Nike separates is the look that turns a tracksuit into an outfit.

Right, now the useful bit — stop guessing your size

Here's the thing that pulls all of the above together. Everything I've just told you is a guideline — and as you've seen, Nike alone shifts fit from line to line and model to model. Cross-shop it against adidas, On, Stone Island and the rest and the guesswork multiplies. That's exactly the problem Tellar was built to solve, and it's why I send every client there.

Tellar: your size in 1,500+ brands, instantly

Tellar is the UK's leading sizing tool. Measure yourself once — bust, waist, hip, or just your existing size in a brand you already trust — and Tellar matches your body precisely to over 1,500 brands. No more squinting at a different size chart on every website.

• Measure once and you're set — use your measurements or a brand size you already know.

• Store Size Lookup gives your exact size in any brand — Nike, adidas, On, COS, Reiss, Arket and more.

• Shop with confidence — no guesswork, fewer returns, better-fitting kit.

• Always free, nothing to download — it runs right in your browser.

And it's completely honest: Tellar is independent, unbiased and unsponsored, so the size it gives you is the size that'll actually fit — nothing more, nothing less.

Find my Nike sizeHow to measure

Beyond the tool, there's the Tellar Fashion Hub — a growing library of free posts from our stylists covering just about every fashion question you can think of. Style advice, top picks, best-brand rundowns, honest fit breakdowns like this one. Always honest, always unbiased, always free. Have a browse below and you'll never buy blind again.

MORE FROM THE TELLAR FASHION HUB

Menswear: The Secret to Smart Casual ComfortThe Best Men's Jeans Brands: High Street, Premium & DesignerHow to Do Casual Style Well: Menswear Brands & Styling Tips

Fit first, logo second — that's always been my rule. Get the size right and even the simplest Nike piece looks like you meant it.