What Is Sizing Like at Circular Clothing Brands?

By Ella Blake — Fashion Stylist | Tellar Fashion Hub — Always honest, unbiased & unsponsored

Sizing at circular and sustainable clothing brands tends to run more true to size than mainstream fast fashion, and often skews slightly smaller — because these labels prioritise natural, woven fabrics over stretch synthetics, and their cuts are frequently more considered and tailored. That said, sizing wildly varies brand to brand, so knowing your measurements before you shop is genuinely essential here.

I'll be honest — I came to circular fashion relatively late. For years I was skeptical. I assumed "sustainable" meant unflattering hemp sacks and sizing that barely acknowledged anything above a size 12. I was wrong on both counts. Once I started digging into this category properly — and started checking my measurements against each brand's size charts — I discovered some of the best-fitting, best-made pieces in my wardrobe. The key is knowing what to expect before you buy.

What Even Is Circular Clothing?

Circular fashion is a design and production model where clothing is made to last, to be repaired, and ultimately to be recycled or returned to the brand at end of life — rather than ending up in landfill. It's the opposite of fast fashion's throwaway model. Brands operating under a circular framework typically:

Use natural, recyclable, or recycled fibres (organic cotton, recycled wool, Econyl, Tencel)
Design for longevity — minimal trend-chasing, classic cuts
Offer take-back or repair schemes
Produce in limited runs or to order to reduce waste

The fashion names doing this well right now include Patagonia, Rapanui, Nudie Jeans, Stella McCartney, Eileen Fisher, Tentree, and UK-based labels like Baukjen and People Tree. Each has slightly different sizing logic — which I'll break down below.

The Core Sizing Challenge with Circular Brands

Here's the thing nobody warns you about: because circular brands are often smaller, independent labels, they frequently lack the sizing standardisation that the big high street players have. There's no centralised sizing bureau telling Rapanui what a UK 12 should measure. Each brand builds its own size chart, and many use XS–XL labelling rather than numbered UK sizes, which adds another layer of guesswork.

I once ordered what I was confident was my size from a sustainable knitwear brand — based purely on the label — and the jumper arrived so narrow across the shoulders it looked like something from a children's range. The lesson? Always measure yourself and check that brand's specific chart. Every. Single. Time.

General Sizing Principles Across Circular Brands

Natural and woven fabrics: Organic cotton, linen, and recycled wool don't stretch like jersey or elastane blends. Size up if you're between sizes — particularly for fitted styles.
Relaxed, considered cuts: Many circular brands deliberately design with ease — slightly roomier through the body to allow for movement and long-term wear. Don't mistake this for "runs big" — check the fit notes carefully.
Limited size ranges: This is improving, but some smaller circular labels still only go to a UK 18 or XL. Always check before falling in love with a piece.
Inconsistent labelling: UK sizing, EU sizing, and XS–XL systems can all appear within the same brand's collection. Go by the measurements, not the label.
Shrinkage: Natural fibres — especially organic cotton and linen — can shrink on first wash. Where brands note this, size up one.

UK to EU Size Conversion — Quick Reference

Sizing at the Most Popular Circular Brands — Brand by Brand

Let me break down the brands I actually know and have researched properly, because vague generalisations aren't useful when you're about to spend £80 on a sustainable jumper.

Patagonia — Sizes True to Size, Slightly Athletic Cut

Patagonia is one of the gold standard circular brands — their Worn Wear programme lets you send back used gear for credit and buy repaired pieces. Sizing runs fairly true to standard UK sizing, though the cut is built around an active, athletic silhouette. If you're curvy through the hip or have a larger bust relative to your waist, sizing up one is sensible. Outerwear tends to be cut for layering, so don't be alarmed if a jacket feels roomy — that's intentional. They offer XS–XXL, and their size guide uses both measurements and XS–XL labelling.

Rapanui — True to Size, Boxy Fits Available

Rapanui, the Isle of Wight brand that started in a garden shed, is one of the most affordable fully circular labels out there. They use organic and recycled cotton and offer sizes XS to 3XL — genuinely inclusive. Their classic tees and hoodies run true to size, but their signature boxy fits are designed to be roomy — if you prefer something more fitted, size down. Every garment has a QR code on the care label for easy returns and recycling. A brand I recommend to friends constantly.

Nudie Jeans — Runs Slightly Small, Size Up in Denim

Nudie Jeans uses organic cotton denim and offers free repairs for life — which is one of the best brand promises in fashion, full stop. Their jeans run on the smaller side, particularly through the waist. If you're between sizes, size up. Denim also stretches slightly with wear, so don't panic if they feel snug initially. They use waist-and-length sizing (like most denim brands), so measuring your actual waist in inches is the most reliable approach.

Eileen Fisher — Runs Large, Intentionally Oversized

Eileen Fisher is the American sustainable brand that has become something of a capsule wardrobe icon for women who want investment pieces that don't shout about trends. Her sizing intentionally runs large and loose — it's a design principle, not an error. If you're used to a fitted silhouette, size down significantly. A UK 12 woman might comfortably wear an XS or S in Eileen Fisher. Their System sizing (1–3, equivalent to XS–XL) is unique to the brand, so always cross-reference with measurements.

People Tree — True to Size, Consistent Across Categories

People Tree is one of the UK's best-loved sustainable brands and arguably the most accessible in terms of sizing consistency. They use UK numbered sizing (6–22 on most styles) and run true to size. Their fabrics are primarily organic cotton and Tencel, both of which can shrink slightly on first wash — cold wash is always recommended. For knitwear especially, check the garment measurements rather than just the size label.

Baukjen — True to Size, Smart Tailoring

Baukjen is a British sustainable brand that actually looks like something you'd find in a premium high street store — proper tailoring, wearable prints, smart occasionwear. Their sizing is consistent and true to UK standard sizing, running from 6 to 20. Fabrics are a mix of sustainable viscose, organic cotton, and recycled fibres. Fitted pieces like blazers and trousers are well-cut for a standard UK hourglass — if you're fuller through the hips, size up in tailored styles.

Tentree — True to Size, but Check Activewear Sizing

Tentree plants ten trees for every item purchased and offers a fully circular take-back programme for used garments. Their casual pieces (tees, sweatshirts, joggers) run true to size or slightly generously. Their activewear, however, uses XS–XL sizing and can run slightly smaller — particularly through the hips. Measuring your bust and hips against their chart is always worthwhile before ordering activewear styles.

High Street Brands to Shop If You Love the Circular Aesthetic

Not every budget stretches to fully circular labels, and that's absolutely fine. These high street names offer strong sustainable ranges or a similar considered-dressing aesthetic:

H&M Conscious Collection — accessible price point, consistent high street sizing, some certified organic cotton pieces
Zara — their Join Life range uses more sustainable materials; sizing runs small so size up one
Mango Committed — their sustainability line uses recycled fibres; Mediterranean sizing tends to run narrow
M&S — reliably true to UK size, increasingly strong on organic cotton basics and sustainable knitwear
White Stuff — relaxed British sizing, good for natural fabric fans; runs true to slightly generous
Fat Face — organic cotton and sustainable ranges; generously cut, brilliant for casual circular-style dressing
Seasalt Cornwall — strong on sustainable fabrics, loose and relaxed fits, very true to size
Boden — some GOTS-certified organic cotton styles; sizing true to UK standard
The White Company — investment-quality sustainable basics; true to size, classic cuts

Independent Picks Worth Knowing

Two brands I've been recommending recently that deserve more attention:

Thought Clothing — a British sustainable brand using bamboo, hemp, and organic cotton. Sizing runs true to UK standard with a lovely relaxed fit. Their knitwear in particular is brilliant quality and sizes consistently.
Beaumont Organic — a UK brand producing beautifully crafted sustainable pieces using GOTS-certified organic cotton. Their sizing is slightly relaxed and considered; perfect for capsule wardrobe building. If you haven't found them yet, you're in for a treat.

Premium & Luxury Circular Options

Stella McCartney — the pioneer of luxury circular fashion. Runs true to standard EU/UK sizing but is cut for a straight, fashion-forward silhouette. If you're curvy, size up in fitted styles.
Vivienne Westwood — sustainability credentials are genuine; sizing is idiosyncratic and runs small. Always measure and check her specific size charts before ordering.
Allbirds — primarily footwear but increasingly wearables; true to size, excellent for the sustainable wardrobe basics crowd.

My Top Tips for Getting Sizing Right

Measure yourself properly — bust, waist, and hips. This is non-negotiable with circular brands given the sizing inconsistency.
Check whether the brand uses XS–XL or numerical UK sizing — they're not always equivalent to what you'd expect.
Look at the garment measurements (not just the size label) for anything woven or structured.
Factor in natural fibre shrinkage — when in doubt, go one size up and wash on cold.
Read the product description carefully for fit notes — circular brands tend to be more honest about how relaxed or fitted a piece runs than high street labels.

Stop Guessing. Let Tellar Do the Work.

Circular brands are brilliant — but their sizing inconsistency is genuinely frustrating. Tellar.co.uk is the UK's leading free sizing tool, matching your exact measurements to 1,500+ brands instantly. No more size chart squinting. No more disappointing returns.

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