What Is Sizing Like at Heresy?

Heresy runs generous and unisex. Its pieces are cut XS to XL on a relaxed, boxy, menswear-leaning block, so if you want a properly fitted look you'll usually want to drop a size (sometimes two) from your high-street norm. If you love that easy, oversized folk-streetwear silhouette the brand is built on, your usual size will sit roomy and gorgeous exactly as intended. There's no hidden trickery here — it's just a London label that cuts things loose on purpose.

I first came across Heresy on a rail in Peckham years ago and made the classic mistake of grabbing a knit in "my size" without thinking. It swallowed me whole. Lovely in a slouchy, throw-it-over-everything way, but not the look I'd had in my head. So let me save you that fitting-room sigh.

The Quick Answer on Heresy Sizing

It's a unisex / menswear-cut brand. Founded in 2012 in South London, Heresy designs around folklore, and the cuts lean roomy and considered rather than body-con.
Pieces run XS–XL (trousers and denim often in a waist measurement, e.g. W30, W32). There's no separate women's grading, so think in terms of the silhouette you want, not the number on the label.
For an oversized look: take your usual high-street size. It'll fall with that dropped-shoulder, lived-in ease.
For a closer, tucked-in look: size down once, sometimes twice on knitwear and hoodies.

How Heresy Fits, Piece by Piece

The fit genuinely varies across the range, so it's worth knowing what you're holding before you commit.

T-shirts: Heresy puts real work into its tees — they're cut on a bespoke boxy block rather than bought-in blanks, so they sit square and slightly cropped rather than long and clingy. They're flattering tucked into a high waist. I'd take my true size for that intended boxy shape, or size down if you want it neater.
Sweats & hoodies: Roomy and dropped-shouldered. If you're between sizes, go smaller unless you specifically want the cocoon effect.
Knitwear: The generous, folk-graphic knits are the most oversized of all. Beautiful slouched over a shirt — but if you want it to skim rather than drown, size down.
Shirts & outerwear: Relaxed, often workwear-inspired with room to layer. Take your usual size if you'll wear knits underneath; size down for a sharper line.
Trousers & denim: Sized by the waist in inches, cut loose and utilitarian. Measure a pair you already love and match the inches rather than guessing.

My Honest Styling Advice

The trick with a brand like Heresy is to let one oversized piece do the talking and keep everything else deliberately neat. An enormous folk-motif knit looks intentional over slim straight-leg jeans and a clean boot; pile it on top of other slouchy layers and you've lost the shape entirely — a mistake I've made on a damp Sunday more than once.

Balance volume with structure. Big knit, narrow bottom half. Boxy tee, high tailored trouser.
Define your waist somewhere. A half-tuck or a belt stops the boxy fit reading as shapeless.
Buy for the silhouette, not the label. With unisex sizing, what matters is how it falls on you — try the size down if in doubt, you can always exchange.

Brands With a Similar Fit & Feel

If you love the relaxed, graphic, slightly folkloric mood of Heresy, here's where else I'd send you across every budget.

High Street

COS — the cleanest oversized cuts on the high street; boxy tees and sculptural knits that capture the relaxed line beautifully.
Uniqlo — superb heavyweight oversized tees and the U range for considered, generous basics at a brilliant price.
Urban Outfitters — the most direct high-street hit for graphic, streetwear-leaning, oversized pieces.
AllSaints — that dark palette and edgy, slouchy knitwear sit right in Heresy territory.
Gap — reliable oversized sweats and blanks with a roomy, casual cut.
Superdry — graphic-heavy casualwear if you want bold motifs without the boutique price.
Whistles — a more polished take on the boxy knit for workwear days.
Levi's — your foundation for the loose denim and workwear co-ord side of the look.

Premium

Toast — the natural fibres, folk-craft sensibility and relaxed cuts are the closest premium cousin to Heresy's whole world.
Brora — for when you want the oversized knit done in proper Scottish cashmere that lasts decades.

Luxury / Designer

Margaret Howell — relaxed British tailoring and knitwear with that understated, considered ease elevated to its finest.
Nigel Cabourn — heritage workwear and vintage military references, beautifully made, if the utilitarian thread is what draws you in.

Two Left-Field Independents Worth Knowing

Story mfg. — naturally dyed, hand-crafted, folk-spirited clothing that shares Heresy's storytelling soul; truly special, slow-made pieces.
Universal Works — Nottingham-based, gently utilitarian and endlessly wearable, with that same easy, unfussy British cut.

Never Guess Your Size Again — Tellar.co.uk

This is exactly the kind of "do I size down?" puzzle I built Tellar to solve. Tellar is the UK's leading sizing tool — your body matched precisely to 1,500-plus brands instantly, so you never have to squint at a confusing size guide again.

Measure once using your bust, waist and hip, or simply 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 many more.
Always free, no downloads, works straight in your browser.

The Tellar Fashion Hub

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Ella Blake — Senior Fashion Stylist & Founder, Tellar