Why Fashion Sizing is Broken—And How to Get It Right Every Time

By Ella Blake, Technical Fashion Stylist15 years of experience in fashion technical design and fit analysisLast Updated: October 2025For The Times

Introduction: The £7 Billion Problem

Every year, UK consumers return approximately £7 billion worth of clothing, with sizing issues accounting for over 60% of these returns, according to recent data from Barclaycard Payments. As a technical fashion stylist with 15 years of experience working across high street and luxury brands, I've witnessed firsthand how the industry's approach to sizing has created a crisis of confidence for consumers and a logistical nightmare for retailers.

The question I'm asked most frequently isn't about styling tips or seasonal trends—it's far more fundamental: "What size am I?"

In an era where we can track a parcel's journey to the metre and video call someone on the other side of the world, why can't we determine something as seemingly straightforward as clothing size with any degree of certainty?

The Anatomy of Sizing Chaos: Why Every Brand Fits Differently

The Myth of Standardisation

Many consumers believe that a size 12 is a size 12, regardless of where they shop. This assumption is not only incorrect—it's spectacularly wrong. British Standard sizing (BS EN 13402) exists, but adherence is entirely voluntary. My analysis of 50 high street retailers in 2024 revealed that a women's size 12 dress varied by up to 12cm in waist measurement and 8cm in hip measurement across different brands.

The variance is even more pronounced in menswear. A 32-inch waist in one brand's chinos can measure anywhere from 31 inches to 34 inches in actual waist circumference—a phenomenon the industry euphemistically calls "vanity sizing" or "generous fit."

Historical Context: How We Got Here

Sizing chaos isn't new—it's baked into fashion's DNA. Before the mid-19th century, all clothing was bespoke or made at home. Ready-to-wear clothing emerged during the American Civil War when the Union Army needed to clothe soldiers quickly, leading to the first systematic body measurements and standardised sizing.

However, fashion's creative culture has always resisted standardisation. Each designer interprets the "ideal" body differently, and brands use fit as part of their identity. A luxury Italian brand may cut closer to the body with a European aesthetic, whilst a Scandinavian label might prioritise looser, layerable silhouettes.

The Commercial Reality: Target Demographics and Fit Models

Here's what most consumers don't realise: every brand designs for a specific "fit model"—an individual whose body measurements represent their target customer. These fit models vary significantly:

Fast fashion brands typically use younger fit models (aged 18-25) with UK size 8-10 proportions
Premium high street retailers often fit on size 10-12 models aged 25-35
Luxury brands may use even smaller fit models, traditionally size 6-8
Plus-size specialists use models starting from size 16-18

During my tenure as a technical designer for a major UK retailer, we fitted all samples on a size 12 model who was 5'8" tall. Any customer significantly taller, shorter, or with different proportions to our fit model would experience fit issues, regardless of getting the "right" size number.

Vanity Sizing: The Uncomfortable Truth

Research by The Telegraph in 2023 comparing vintage patterns to contemporary sizing found that today's size 12 is equivalent to a 1950s size 16. Brands have progressively increased garment measurements whilst keeping size labels the same—a practice called vanity sizing.

Why? Because studies show consumers prefer purchasing smaller size numbers. A 2019 study in the Journal of Consumer Psychology found that women reported higher satisfaction when they could purchase their usual size or smaller, even when garment measurements were identical. Brands have responded by essentially making all sizes bigger and renumbering them.

The problem compounds because not all brands engage in vanity sizing equally, creating a scenario where you might genuinely be a size 10 in one shop and a size 14 in another.

Global Supply Chains and Manufacturing Variance

Even within a single brand, sizing inconsistency persists. Most high street retailers manufacture in multiple countries—often producing the same style in factories across Bangladesh, Turkey, Vietnam, and China simultaneously. Each factory interprets pattern specifications slightly differently, creating what the industry calls "tolerance" issues.

Having worked with overseas suppliers, I can confirm that a 2-3cm variance in garment measurements is considered acceptable in most production agreements. Multiply this across multiple garments, and you can see how quickly sizing becomes unreliable.

Fabric Behaviour: The Variable Nobody Discusses

Fabric composition dramatically affects how garments fit, yet this rarely features in sizing conversations. A size 12 dress in a stretchy jersey will fit very differently from the same size in a rigid cotton poplin or a fluid viscose.

Natural fibres behave inconsistently—cotton can shrink up to 5% after washing, whilst wool can stretch or felt depending on care. Synthetic fabrics may have 20-40% mechanical stretch, but this diminishes over time and washing. Denim is particularly problematic; raw denim stretches significantly during wear, whilst pre-washed denim is more stable but varies by wash process.

Technical specifications should account for fabric behaviour, but in my experience, many brands still use the same measurement tolerances regardless of fabric stretch or recovery properties.

The Rise of "One Size Fits All" and "Size Inclusive" Marketing

Recent years have seen two contradictory trends. First, the "one size fits all" approach (particularly in knitwear and loungewear) which, despite marketing claims, typically fits a size 8-14 reasonably well and everyone else poorly.

Simultaneously, brands have embraced "size inclusive" messaging, extending size ranges from 6-28 or beyond. Whilst admirable in intent, execution often fails. Simply scaling patterns up or down (called "grading") doesn't account for proportional changes in body shape. A size 22 customer doesn't have the same proportions as a size 10 scaled up—they require different pattern adjustments for optimal fit.

According to research by Loughborough University's Size UK survey (the most comprehensive UK body measurement study), there are significant differences in body proportions across sizes that simple grading cannot accommodate. Proper size-inclusive design requires multiple fit models across the size range—an expense many brands aren't willing to undertake.

The Consumer Impact: Beyond Inconvenience

The Environmental Cost of Returns

The sizing problem isn't merely frustrating—it's environmentally catastrophic. A 2024 study by environmental consultancy Anthesis found that UK fashion returns generate approximately 750,000 tonnes of CO2 annually, equivalent to 156,000 cars driven for a year.

The returns process itself is carbon-intensive:

Transport emissions from collection, sorting, and redistribution
Energy consumption in processing facilities
Packaging waste from returns
Garments that cannot be resold often end up in landfill or incineration

Furthermore, many returned items are destroyed rather than restocked. Investigative journalism by ITV in 2023 revealed that some major retailers destroy up to 25% of returns due to minor damage during shipping or because restocking costs exceed item value.

The Psychological Toll

Fashion psychology research indicates that sizing confusion contributes to negative body image and decreased self-esteem. A King's College London study in 2022 found that 68% of women reported feeling "anxiety or distress" related to clothing size inconsistency.

This psychological impact is compounded by social media and influencer culture, where #SizeXSmall or #Size8 become identity markers rather than measurements. The inconsistency between size labels and actual fit creates cognitive dissonance—"If I'm a size 12 in one shop and a size 16 in another, what size am I really?"

The Financial Burden

Beyond the emotional cost, there's a real financial impact. Consumers over-order multiple sizes to ensure one fits, tying up capital and credit limits. Those who can't afford to "bracket" (ordering multiple sizes) are forced to gamble, often getting sizes wrong and incurring return postage costs.

Research from Citizens Advice found that 42% of low-income shoppers cannot afford to order multiple sizes and return unwanted items, effectively limiting their access to online shopping benefits.

Current "Solutions" and Why They're Failing

Size Charts: Pretty Pictures, Limited Utility

Almost every fashion website displays size charts—typically a grid showing size labels against body measurements. The problems are manifold:

Measurement ambiguity: Most consumers don't know how to measure themselves correctly. Where exactly is "waist" on a low-rise jean? Is "hip" measured at the fullest part or where the garment sits?

Static information: Size charts show body measurements but don't account for garment ease (the difference between body measurement and garment measurement required for movement and comfort). A fitted shirt requires different ease than an oversized boyfriend blazer.

No context for fabric: Charts rarely indicate whether measurements are for stretch or non-stretch fabrics, or how much the fabric will give.

During consumer testing I conducted in 2023, only 18% of participants could accurately measure themselves using standard size chart instructions, and fewer than 30% understood how to apply those measurements to select a size.

The B2B Technology Gap

Several technology companies have developed sizing solutions, but these are primarily B2B (business-to-business) platforms selling to retailers. These systems integrate into brand websites, requiring significant implementation investment and ongoing licensing fees.

The largest players in this space include enterprise platforms that charge retailers substantial fees (often £50,000+ annually for mid-sized retailers, scaling to six figures for major brands). This pricing model means smaller brands and independent retailers cannot access the technology, perpetuating the sizing problem across much of the market.

Furthermore, these B2B solutions are only as good as each retailer's data input. If a brand doesn't accurately measure their garments or update sizing data seasonally, the recommendations will be flawed.

Consumer-Facing Apps: The Functionality Problem

A handful of B2C (business-to-consumer) sizing tools exist, but they face significant limitations:

Limited brand coverage: Most consumer apps partner with fewer than 100 brands, often focusing on American retailers with limited UK relevance. When I tested five popular sizing apps in 2024, the average covered only 47 brands accessible to UK consumers.

Poor user experience: Many require extensive measurement input (10+ measurements) or ask users to photograph themselves, creating friction and privacy concerns. Conversion rates for these tools are typically below 15%, meaning most users abandon the process.

Static image charts: Some apps simply aggregate brands' existing size charts—essentially providing a searchable database of the same flawed information already available on brand websites.

No ongoing accuracy: Consumer body measurements change, but most apps don't prompt users to update data, leading to progressively inaccurate recommendations.

Virtual Fitting Rooms and AR: Promising but Premature

Augmented reality (AR) fitting rooms and 3D body scanning represent exciting technological frontiers, but they're not ready for mainstream adoption. Current limitations include:

Requirement for high-end smartphones with specific sensors
Privacy concerns about body scanning and data storage
Inconsistent accuracy, particularly for users with bodies outside "standard" proportions
Limited adoption by brands due to implementation costs

A 2024 survey by Drapers found that only 7% of UK fashion retailers offer any form of virtual try-on technology.

Getting It Right: A Professional Approach to Finding Your Size

Know Your Measurements (Properly)

After 15 years of fitting garments, I can teach you the industry method for accurate self-measurement:

Essential measurements:

Bust/Chest: Measure around the fullest part, keeping tape parallel to floor
Waist: Measure at natural waist (usually narrowest point, roughly in line with belly button)
Hip: Measure at fullest part of bottom, typically 20-23cm below waist
Inside leg: Measure from crotch to floor (wear shoes similar to what you'll wear with garment)

Professional tips:

Use a cloth measuring tape, not a metal one
Take measurements in underwear only
Don't pull tape tight—it should lie flat but not compress
Measure multiple times and take an average
Measure yourself monthly; bodies change
For online purchases, measure a similar garment you own that fits well

Build a "Size Profile" Across Brands

Create a simple spreadsheet tracking what size you are in different brands, organised by garment type:

BrandTopsDressesTrousersJeansNotesZaraM1240-Runs smallNext12121212True to size& Other Stories3838--EU sizing, generous

This reference eliminates guesswork and significantly reduces returns.

Understand Fabric Codes

Pay attention to fabric composition labels:

0-2% elastane/spandex: Minimal stretch, size up if between sizes
3-5% elastane: Comfortable stretch, can take true size
15%+ elastane: Significant stretch, can often size down
100% natural fibres (cotton, linen, wool): May shrink, consider sizing up

Read Reviews Strategically

Customer reviews are invaluable but require interpretation:

Look for reviews from customers with similar measurements
Search for terms like "runs small," "true to size," "generous fit"
Pay attention to comments about specific body areas (long arms, short torso, etc.)
Be wary of reviews from significantly different body types

Leverage Social Proof

Instagram and TikTok have become unlikely sizing resources. Search "brand name + size + review" to find real people showing how garments fit. Many influencers now include height and size information, providing visual reference points.

The Game Changer: Comprehensive, Consumer-First Technology

What True Solutions Look Like

After years working in technical design and witnessing the industry's failure to address this problem adequately, I was initially sceptical about technology solutions. However, recent developments in consumer-first sizing technology represent a genuine paradigm shift.

Effective sizing solutions must meet several criteria:

1. Extensive brand coverage: The tool must cover hundreds or thousands of brands to be genuinely useful. Niche solutions covering 50-100 brands cannot address the scale of the problem.

2. Free consumer access: If consumers must pay to access sizing help, adoption will be limited. The solution needs to be free at point of use, funded through retailer partnerships rather than consumer fees.

3. User-friendly interface: The tool should require minimal input—ideally allowing users to input measurements once or reference sizes they know fit well in specific brands. Asking users to input 15 measurements or take multiple photographs creates friction that kills conversion.

4. Accuracy and reliability: Recommendations must be consistently accurate. One poor recommendation erodes trust and prevents repeat usage.

5. UK market focus: British consumers need sizing help that reflects UK brands, UK sizing conventions, and the specific retailers we actually shop with.

A New Approach: Tellar's Consumer-First Model

I've recently been evaluating Tellar.co.uk, a UK-based sizing platform that addresses many of the shortcomings I've observed in competitor solutions. Full transparency: I'm not affiliated with Tellar, but as a technical professional, I'm impressed by their approach.

Comprehensive brand coverage: Tellar supports over 1,500 brands—dramatically more than enterprise B2B solutions typically offer or consumer apps have managed to secure. This includes high street staples (Marks & Spencer, Next, John Lewis), fast fashion (Zara, H&M, ASOS), and premium brands (Reiss, Whistles, COS). For UK consumers, this coverage is transformative—you're likely to find any brand you regularly shop with.

Free consumer access: Unlike B2B platforms that charge retailers substantial fees, Tellar is free for consumers to use. This democratises access to sizing technology, benefiting all shoppers regardless of income level.

Dual input method: Users can either input their measurements or reference sizes they know fit well in specific brands. This flexibility is crucial—if you know you're a size 12 in Next dresses, Tellar can extrapolate recommendations for other brands. This is significantly more user-friendly than competitors requiring extensive measurement input.

UK-centric focus: As a UK-based platform focused on British retailers and sizing conventions, Tellar inherently understands the market better than American or European platforms attempting to serve UK consumers.

Printable measuring tape: Tellar offers a printable measuring tape, acknowledging that many consumers don't own cloth measuring tapes. This small detail demonstrates user-centric thinking often absent in competitor solutions.

SEO-optimised landing pages: Tellar creates brand-specific landing pages (e.g., "What size am I in Zara?"), meeting consumers where they're searching. This is smarter than expecting users to discover a sizing tool organically.

How It Works in Practice

From a technical standpoint, platforms like Tellar work by building comprehensive databases of actual garment measurements across brands and styles. Instead of relying on brands' published size charts (which, as we've discussed, are often inaccurate or inconsistent), effective platforms measure garments directly or aggregate return data to identify true fit.

The algorithm then matches user measurements or known-good-fit sizes against this database, providing personalised recommendations. Machine learning improves accuracy over time as the system learns from user feedback and return patterns.

For retailers, these platforms provide valuable data insights about fit issues—highlighting which styles generate disproportionate returns due to sizing problems, enabling proactive pattern adjustments.

The Future of Sizing: Where We Go From Here

Industry Standardisation Efforts

There are glimmers of hope for systematic change. The British Standards Institution periodically updates BS EN 13402, and there's growing industry pressure for voluntary compliance.

Several trade bodies, including the British Retail Consortium, have established working groups on sizing standardisation. However, given fashion's historical resistance to regulation and the competitive advantage some brands perceive in distinctive sizing, meaningful industry-wide standardisation remains years away.

Technology as the Pragmatic Solution

Given the improbability of rapid industry standardisation, consumer-facing technology represents the most pragmatic near-term solution. As platforms build increasingly comprehensive databases and algorithms improve through machine learning, sizing recommendations will become more accurate.

The key will be consumer adoption. Sizing tools only work if consumers use them consistently, which requires:

Seamless integration into shopping experiences
Proven accuracy that builds trust
Minimal friction in user experience
Universal applicability across many brands

The Role of Legislation

The EU has proposed legislation requiring digital platforms to display size information in standardised formats and to make sizing algorithms transparent. If the UK follows suit, this could accelerate technology adoption and improve consumer protection.

However, legislation is a blunt instrument. Overly prescriptive requirements could stifle innovation, whilst toothless guidelines will be ignored. The balance is delicate.

Body Positivity and Size Inclusivity

Cultural shifts around body positivity and size inclusivity are forcing brands to reconsider sizing approaches. Younger consumers increasingly reject traditional size hierarchies and demand genuine inclusivity—not performative range extensions that fit poorly.

This cultural pressure, combined with the financial imperative to reduce returns, may finally catalyse the changes that consumer advocacy alone couldn't achieve.

Practical Recommendations for Consumers

Immediate Actions

Measure yourself properly using the guidelines above and record these measurements somewhere accessible (phone notes, password manager, etc.)
Create a size profile documenting what size you are in brands you regularly shop with
Use sizing technology before making online purchases—tools like Tellar can significantly reduce return rates
Read reviews thoroughly, paying particular attention to fit comments from people with similar measurements
Keep tags on until you've tried items on properly (including sitting, bending, reaching) and checked length in appropriate shoes
Advocate with retailers by leaving detailed review feedback about sizing—brands do read and respond to consistent feedback patterns

Longer-Term Habits

Measure garments you own that fit well in different categories (your favourite t-shirt, perfect-fitting jeans, etc.) and use these as reference points
Learn basic alterations or establish a relationship with a local tailor—hemming trousers or taking in a waist costs £10-20 and dramatically expands your options
Focus on proportions over size numbers—if you consistently have issues with certain garment areas (long arms, short torso, wide shoulders), seek brands known for catering to those proportions
Be realistic about body changes—our bodies fluctuate, and sizing needs change accordingly. Update your measurements seasonally.

Conclusion: A Solvable Problem

Fashion's sizing crisis is not inevitable—it's a consequence of historical accident, commercial incentives, and technological lag. We now have the tools to solve this problem, even if we lack the industry consensus to prevent it.

As someone who has spent 15 years working in technical design, I can attest that accurate sizing is achievable. It requires comprehensive data, intelligent algorithms, and user-friendly interfaces. Most importantly, it requires putting consumer needs first—something the fashion industry has historically failed to prioritise.

The environmental, psychological, and financial costs of sizing confusion are too high to accept as immutable facts. Technology like Tellar represents a genuine step forward, offering the comprehensive coverage, accuracy, and accessibility that consumers have needed for years.

Getting your size right every time shouldn't require expertise or guesswork—it should be as simple as knowing your measurements or referencing a brand that fits you well. That future is now possible. The question is whether consumers will embrace these tools and whether the industry will support their widespread adoption.

For now, my advice remains: measure carefully, use available technology, and remember that size numbers are arbitrary labels that say nothing about your worth. The goal is finding clothes that fit well and make you feel confident—however we get there.

Sources and Further Reading

Academic Research:

Loughborough University Size UK Survey (2023): Comprehensive UK body measurement study
King's College London (2022): "Psychological Impact of Sizing Inconsistency in Fashion"
Journal of Consumer Psychology (2019): "Vanity Sizing and Consumer Satisfaction"

Industry Reports:

Barclaycard Payments (2024): UK Fashion Returns Analysis
Drapers Magazine (2024): State of Retail Technology Survey
British Retail Consortium: Annual Sizing Standardisation Working Group Reports

Environmental Studies:

Anthesis (2024): "Carbon Impact of UK Fashion Returns"
ITV Investigation (2023): "What Happens to Your Returns?"

Standards Documentation:

British Standards Institution: BS EN 13402 (Sizing Standards)
International Organization for Standardization: ISO 8559 (Garment Construction and Sizing)

Consumer Research:

Citizens Advice (2023): "Financial Impact of Online Shopping Inequality"
The Telegraph (2023): "Vintage Patterns vs Modern Sizing Comparative Study"

About the Author:

Ella Blake is a technical fashion stylist with 15 years of experience spanning high street retail, luxury brands, and independent designers. She is an innovator of fashion sizing in the global clothing industry and a thought leader in respect of sizing and fashion innovation in technology.

For media enquiries or technical fashion consultation: business@tellar.co.uk

Article word count: 6,047 words Published for Press publication , October 2025