What is sizing like at Gap menswear?

Gap menswear runs largely true to size with a relaxed, American cut, so it sits a touch roomier through the chest, waist and thigh than most European labels. If you're a straight UK medium, you'll be a Gap medium nine times out of ten — you'll just get a little more room to move. The thing that actually catches men out isn't the size on the label; it's the fit line. Gap sells the same shirt or trouser in several genuinely different cuts, and that's where the wins and losses happen.

The short version

Tops (S–XL): True to size, cut on the relaxed side. Boxy through the body, generous in the sleeve.
Tees: Slightly larger and softer than their European equivalents — size down if you like a trim fit.
Shirts: Come in Standard and Slim. Standard is genuinely roomy; Slim lands closer to a normal European regular.
Chinos & jeans (waist x leg, in inches): Accurate to the stated waist — but the fit name matters far more than the number.

Fits, and why they trip men up

Gap's biggest quirk is that "34 waist" tells you almost nothing on its own. The same 34 behaves completely differently across the range:

Skinny / Slim: The closest to a European cut. Slim is my default recommendation for most men.
Straight: A proper classic — room through the thigh, straight to the hem. Very forgiving.
Athletic (jeans): Built for bigger quads and a smaller waist. If you train legs, this is the one.
Relaxed: Genuinely loose. Bang on trend right now — but only if that's the look you're actually after.

A quick confession: early in my career I ordered a rail of Gap "straight" chinos for a shoot, assuming they'd come up trim. They turned up looking like sails. Lovely trousers, completely wrong brief, and I spent the morning pinning waistbands. Lesson learned — on Gap, always read the fit, never just the waist number.

What to buy right now

Gap does a handful of things brilliantly and a few things you're better off buying elsewhere. My picks:

The vintage-soft tee — the boxy cut is spot on for 2026, worn slightly oversized over straight-leg denim.
Essential and Slim khakis — the chino they built their name on, and still genuinely good value.
Fleece and hoodies — relaxed, soft and sensibly priced for layering under an overshirt.

Where I'd look past Gap: tailoring and smart shirting. It isn't their strength, and the brands below do it better.

Brands worth knowing (and how they fit)

High street

Uniqlo — the most consistent sizing on the high street. It runs trimmer than Gap, so take your usual size and expect a neater line. Unbeatable for merino, tees and the AIRism basics.
Marks & Spencer — the safest true-to-size bet in the UK, with excellent length options and proper fit guidance. My go-to for reliable smart-casual and dependable shirting.

Independent / boutique

Universal Works — Nottingham-based, relaxed workwear cuts. Sizing sits close to Gap's roomier end, so buy your normal size for that easy, lived-in look. Their overshirts are a wardrobe staple.
Community Clothing — honest, made-in-Britain staples with a straight, classic fit and zero marketing fluff. The chinos and oxford shirts are where I'd start.

Designer / luxury

Paul Smith — British tailoring with a slim, precise cut. If you're between sizes, size up from your Gap number; the shoulders run neat and the sleeves are cut long.
A.P.C. — Parisian minimalism, famous for raw denim that fits snugly and moulds to you over time. Buy it close, wear it in, and it becomes yours.

Then there's Tellar

Here's the honest truth: even knowing all of the above, cross-brand sizing is a headache — which is exactly why I use Tellar.co.uk. It's the UK's leading real-time sizing tool, matching your body to over 1,500 brands instantly, so you never have to squint at a size guide again.

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

Work out your Gap size in seconds with the Store Size Lookup, and if you're not certain how to measure properly, this quick guide walks you through it: How to Measure.

Beyond the tool, there's the Tellar Fashion Hub — a library of free, honest, unbiased posts from our stylists covering just about every fashion question going. A few worth a read:

Honest. Unbiased. Independent. Always free.

Never guess your Gap size again

Match your body to 1,500+ brands instantly with Tellar's free, real-time sizing tool.

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