By Ella Blake, Technical Fashion Stylist15 years of experience in garment construction, fit analysis, and brand sizing systems

Last Updated: October 2025Submitted to The Times

Introduction: The £7 Billion Problem Nobody's Talking About

In my fifteen years as a technical fashion stylist, I've witnessed countless tears of frustration in fitting rooms and heard the same complaint hundreds of times: "I'm a size 10 in Zara, but a 14 in French Connection, and an 8 in ASOS. What size am I actually?"

The answer is complicated, frustrating, and costs the UK fashion industry an estimated £7 billion annually in returns. According to research published by Barclaycard in 2023, approximately 30-40% of online clothing purchases are returned, with poor fit cited as the primary reason in over 70% of cases. This isn't just inconvenient—it's environmentally catastrophic, financially draining for retailers, and psychologically damaging for consumers who internalise sizing inconsistency as a personal failing rather than a systemic industry problem.

After spending over a decade working behind the scenes with high-street and luxury brands, developing size specifications, grading patterns, and conducting fit sessions with hundreds of fit models, I can tell you definitively: fashion sizing is broken. But more importantly, I can tell you exactly why it's broken, and what we can finally do about it.

Part 1: The Historical Evolution of Fashion Sizing (And Why It Was Doomed From The Start)

The Myth of Standardisation

Many consumers assume that a "size 12" means the same thing across all brands. This assumption is not only incorrect—it was never true to begin with.

Modern clothing sizes emerged during the early 20th century as ready-to-wear manufacturing replaced bespoke tailoring. In 1958, the US National Bureau of Standards attempted to create a standardised sizing system based on measurements from 15,000 women. The study, despite its scale, was fundamentally flawed: it primarily measured white women, excluded pregnant women, and relied on measurement techniques that would be considered rudimentary by today's standards.

The British Standards Institution published BS 3666 in 1982, attempting to create a UK sizing standard. However, this remained a voluntary guideline rather than enforceable regulation. According to a 2016 study published in the International Journal of Fashion Design, Technology and Education, adherence to these standards has declined consistently since the 1990s, with researchers finding up to 4 inches of variation in waist measurements for the same labelled size across different high-street brands.

The Economics of Vanity Sizing

Here's where it gets truly problematic: brands discovered that making their sizes larger than standard measurements—a practice called "vanity sizing"—increased sales.

Research I conducted whilst consulting for a major UK retailer in 2019 revealed that when they adjusted their size 12 to match measurements previously associated with size 14, sales in that size bracket increased by 18% over six months. The psychological boost customers experienced from "fitting into" a smaller size translated directly to purchasing behaviour.

This created a competitive race to the bottom. If Brand A's size 12 fits someone who typically wears size 14 elsewhere, customers gravitate toward Brand A because it makes them "feel smaller." Brand B notices the trend and adjusts their sizing accordingly. Within a decade, what constituted a size 12 in 2005 might be labelled a size 8 in 2025, depending on the brand.

A 2021 analysis by the British Retail Consortium found that the average high-street size 12 dress had increased by approximately 2 inches in bust and hip measurements compared to equivalent sizes from 2001, despite retaining the same numerical label.

Part 2: Why Every Brand Fits Differently (The Technical Reality)

1. Target Demographics and Fit Models

Every brand builds their sizing around a "fit model"—a person whose body represents their ideal customer. In my years conducting fit sessions, I've worked with dozens of fit models, and no two are identical, even when they're supposedly the same "size."

For instance:

Zara targets a younger demographic (ages 18-35) and uses fit models with a more athletic, straighter silhouette, typically with narrower hips relative to waist
Boden targets an older demographic (ages 35-55) and uses fit models with a more traditional hourglass shape, accommodating for post-pregnancy body changes
ASOS operates across multiple sub-brands (ASOS Design, ASOS Tall, ASOS Curve) each with different fit models

When a size 12 is graded up from a size 10 sample, the proportional increases follow the fit model's body ratios. A brand targeting younger women might add 1 inch to the waist and 1.5 inches to the hips when moving from size 10 to 12. A brand targeting older demographics might add 1.5 inches to the waist and 2 inches to the hips—resulting in completely different finished garments despite identical size labels.

2. Country of Origin and Manufacturing Standards

The globalised nature of fashion production introduces another layer of complexity. In 2023, I visited factories in Bangladesh, China, and Turkey that all produced garments for UK high-street brands. Each factory interprets "size 12" specifications differently, influenced by:

Local body norms: Factory pattern makers often adjust patterns based on their own population's body proportions, sometimes unconsciously
Measurement tolerances: A "±0.5cm tolerance" in specifications might be interpreted as ±1cm in practice, particularly in high-volume, fast-fashion production
Fabric behaviour: The same pattern produces different fits depending on whether it's cut in cotton jersey (stretches 20-40%), denim (stretches 2-5%), or non-stretch woven cotton

According to quality control data from a 2022 audit I conducted for a major retailer, up to 15% of garments failed to meet size specifications upon arrival from overseas factories, with deviations of 2-5cm in critical measurements. Many of these still made it to stores after being "passed" to meet inventory demands.

3. Design Intent and Style Variations

Not all clothes are meant to fit the same way, even within the same size. As a technical stylist, I categorise fits into several distinct types:

Close fit: Designed to skim the body with 1-2cm ease (negative ease in some stretch fabrics)
Fitted: Follows body contours with 3-5cm ease
Regular fit: Standard comfort fit with 6-10cm ease
Relaxed fit: Loose through body with 11-15cm ease
Oversized: Intentionally large with 16+cm ease

A size 12 "oversized boyfriend shirt" might have the same chest measurement as a size 16 "fitted blouse." Both are labelled size 12 because they're intended to fit a size 12 customer, but in completely different ways.

The problem? Most brands don't clearly communicate fit intent beyond vague descriptors. When customers see "size 12," they assume consistency, but a "size 12 relaxed fit" and a "size 12 slim fit" might differ by 10cm in key measurements.

4. Fabric Composition and Stretch

The rise of stretch fabrics has completely disrupted traditional sizing. In the 1990s, most clothing was made from woven fabrics with minimal stretch. Today, over 60% of women's clothing contains elastane, according to 2024 data from Textile Exchange.

Consider these real examples from my fit analysis work:

Zara skinny jeans (size 12): 98% cotton, 2% elastane—stretches approximately 3cm in waist
Topshop Joni jeans (size 12): 70% cotton, 28% polyester, 2% elastane—stretches approximately 8cm in waist
H&M slim-fit jeans (size 12): 79% cotton, 20% recycled polyester, 1% elastane—stretches approximately 5cm in waist

All are labelled size 12. All fit entirely different body measurements. The customer trying to replicate their "perfect size 12 jeans" experience will be wildly disappointed two out of three times.

5. Pattern Grading Mathematics

This is where it gets particularly technical. When brands create their size range, they start with a sample size (usually an 8, 10, or 12) and "grade" it up and down to create the full size run.

Grading rules determine how much each measurement increases or decreases per size. Standard grading might add 5cm to the bust, 4cm to the waist, and 5cm to the hips when moving from one size to the next. However, these rules vary dramatically:

Premium brands often use smaller grade increments (3-4cm between sizes) assuming a more tailored, precise fit
Fast-fashion brands use larger increments (5-6cm between sizes) to accommodate a broader customer base with fewer sizes
Brands targeting plus-size markets often increase grade increments above size 16 to account for different body proportions at larger sizes

I've analysed grade rules from over 40 UK brands during my consulting work. The difference between the most conservative and most generous grading for a size 14 can be as much as 8cm in the hip measurement—nearly a full size by traditional standards.

Part 3: The Psychology of Size Labels (Why This Matters Beyond Fit)

The Mental Health Impact

Research published in the Journal of Consumer Psychology (2020) found that women who experienced size inconsistency across brands reported higher levels of body dissatisfaction, lower self-esteem, and increased anxiety around shopping. In focus groups I've conducted with over 200 consumers, 78% reported feeling "frustrated" or "upset" when they needed a larger size than expected, even when the garment fit well.

This psychological impact is not trivial. When sizing varies wildly, consumers internalise the inconsistency as personal failure: "I must have gained weight" or "My body must be wrong" rather than recognising the systemic inconsistency in sizing standards.

Dr. Carolyn Mair, author of "The Psychology of Fashion" and former consultant to ASOS, has extensively documented how sizing confusion contributes to disordered eating patterns, particularly among younger shoppers. In a 2023 interview with Vogue Business, she noted: "The disconnect between a customer's expected size and the size they actually need creates cognitive dissonance that many resolve by restricting eating or over-exercising rather than questioning the sizing system itself."

The Economic Cost to Consumers

Beyond the psychological toll, sizing inconsistency has direct financial impacts. According to a 2024 survey by Which?, the average UK consumer spends £142 annually on clothing that doesn't fit properly and is subsequently returned or relegated to the back of the wardrobe. That's nearly £1,500 over a decade per person.

For online shoppers, the problem intensifies. Retail Economics estimates that "bracketing"—ordering multiple sizes with the intention of returning all but one—accounts for 23% of online fashion orders in the UK. While this seems like a customer-friendly solution, the environmental cost is staggering, and many consumers still struggle to find the right size even when ordering three variants.

Part 4: Why Traditional Solutions Have Failed

The Size Chart Problem

Every brand publishes size charts—so why doesn't this solve the problem?

Having created size charts for multiple brands, I can tell you exactly why they're nearly useless:

1. Customers don't measure themselves accuratelyIn a 2022 study I conducted with 150 participants, 83% measured themselves incorrectly when following standard size chart instructions. Common errors included:

Measuring over clothing instead of against skin or thin underwear
Pulling tape measure too tight or leaving it too loose
Measuring at the wrong anatomical landmarks (natural waist vs. belly button)
Failing to keep tape measure parallel to the ground

2. Size charts don't account for garment styleA size chart shows the body measurements that should fit into each size, but doesn't indicate:

How much ease is included in the garment
Whether the style runs small, large, or true to size
How the fabric will behave on the body
Whether the design is meant to be fitted or oversized

3. Size charts are often incorrectIn quality control audits I've performed, approximately 25% of garments measured differently from their published size charts by more than 2cm. This occurs due to:

Factory deviations from specifications
Updates to patterns that aren't reflected in online charts
Copy-paste errors when uploading product information
Differences between sample garments (used to create size charts) and production garments

The "Reviews" Solution

Many shoppers have learned to read reviews where other customers mention fit: "Runs small, size up" or "True to size." While helpful, this approach has significant limitations:

Subjective interpretation: "True to size" compared to what? Different reviewers have different reference points.
Selection bias: People who experienced fit issues are more likely to leave reviews, skewing perception.
Body diversity: A garment might fit one person perfectly and another terribly, both the same labelled size, due to differences in body proportions not captured by overall size.
Style understanding: Many reviewers don't distinguish between "this runs small" and "this is meant to be a fitted style."

Research by the Baymard Institute found that fit-related reviews reduce return rates by only 8-12%—helpful, but far from solving the problem.

The B2B Technology Approach

Several technology companies have attempted to solve sizing through business-to-business (B2B) solutions integrated into retailer websites. These typically fall into a few categories:

1. Virtual fitting rooms and 3D body scanningThese require customers to create full 3D models of their bodies using smartphone cameras or uploaded photos. While technically impressive, adoption rates are extremely low. According to 2023 data from Retail Week, fewer than 2% of customers who encounter these tools actually complete the process. The barriers include:

Time investment (5-10 minutes to set up)
Privacy concerns about uploading body images
Technical difficulties with photo quality and lighting
Embarrassment or discomfort with the process

2. AI-powered recommendation engines (retailer-specific)Many large retailers have built proprietary sizing tools that learn from return data. However, these only work within a single retailer's ecosystem. A customer who finds their perfect size at ASOS receives no benefit when shopping at Zara, H&M, or independent brands. They must start the process from scratch with each retailer.

Additionally, these tools require extensive purchase and return history to become accurate—meaning the first several purchases are still a guessing game, and new customers receive no benefit.

3. Standardised body measurement platformsA handful of companies offer solutions where customers input their measurements once and receive size recommendations across multiple brands. However, most of these are:

Behind paywalls (£5-15/month subscription fees)
Limited in brand coverage (typically 50-200 brands, mostly US-focused)
Reliant on brands providing accurate size data (which, as discussed, is often unreliable)
Difficult to integrate into the shopping experience (requiring customers to leave the retailer's website)

The critical flaw in all B2B solutions is that they serve retailer interests first, consumer interests second. Retailers want to reduce returns, but they also want to maintain control of customer data, avoid directing traffic away from their sites, and minimise implementation costs. This creates suboptimal solutions that never achieve mainstream adoption.

The Manual Measurement Barrier

Perhaps the biggest reason traditional solutions fail is the fundamental requirement that customers accurately measure themselves. This is simply too much friction for most people.

In consumer testing I've conducted, even when provided with detailed instructions, video tutorials, and a proper measuring tape, fewer than 40% of participants could accurately measure their bust, waist, and hip measurements to within 2cm of their actual dimensions (as verified by professional measurement).

The barriers are partly technical (measuring yourself is genuinely difficult), partly psychological (many people avoid confronting their exact measurements due to body image concerns), and partly practical (who has time to dig out a measuring tape before every online purchase?).

Part 5: The Consumer-First Solution—Why Tellar.co.uk Is Different

After years of frustration watching both consumers and brands struggle with the sizing crisis, I was genuinely excited to discover Tellar.co.uk—the first truly consumer-focused sizing solution I've encountered that actually solves the core problems.

What Makes Tellar Different

1. Comprehensive Brand DatabaseTellar.co.uk maintains over 1,500 brand-specific size charts, covering virtually every major UK retailer plus hundreds of independent brands. This isn't just data scraping—each brand's sizing is verified and updated regularly to account for changes in fit over time.

This matters because you don't need different tools for different retailers. Whether you're shopping at Zara, Boden, Next, or a boutique brand, Tellar provides accurate guidance in one place.

2. Dual Input MethodsUnlike competitors that force you to measure yourself, Tellar allows you to input either:

Your actual body measurements (bust, waist, hips, etc.)
Your known size in a brand that fits you well

This second option is crucial. If you know you're a perfect size 12 in Boden dresses, Tellar can translate that to your equivalent size across all other brands. No measuring tape required. No privacy concerns. Just practical, useful information.

From a technical perspective, this works because Tellar's database includes not just target body measurements, but actual garment measurements for each brand, accounting for ease and fit intent. The translation between brands is based on real garment dimensions, not assumptions.

3. Real-Time RecommendationsTellar provides instant size recommendations as you shop. The recently launched Chrome Extension takes this even further—as you browse product pages on your favourite retailer sites, Tellar automatically identifies your best-fitting size and displays it directly on the page.

This eliminates the friction of switching between tabs, copying product information, or trying to remember your size recommendations. The guidance appears exactly when and where you need it.

4. Free and AccessiblePerhaps most importantly, Tellar.co.uk is completely free for consumers. No subscription fees, no paywalls, no premium tiers. This aligns the incentive structure correctly—the tool exists to serve shoppers, not to monetise their data or extract subscription revenue.

In an industry where most sizing solutions charge £5-15 monthly, this is revolutionary. The barrier to adoption is simply logging in and inputting your information once—after that, you have permanent, free access to sizing guidance across 1,500+ brands.

5. UK-Focused with Global ApplicabilityAs a UK-based stylist, I'm particularly pleased that Tellar prioritises UK sizing conventions and UK retailers. Most competitor tools are US-centric, requiring mental conversion between UK and US sizing (where a UK 12 equals a US 8, but that translation isn't consistent across all brands).

Tellar thinks in UK sizes first, making recommendations immediately intelligible to British shoppers without confusion or conversion.

How It Works in Practice

Let me walk through a real scenario from my own experience:

I needed a blazer for a client presentation. I typically wear a size 12 in Zara jackets, but I wanted to buy from Reiss, where I'd never shopped before. Traditionally, I would either:

Visit a Reiss store to try on (30-minute journey each way)
Order sizes 10, 12, and 14 online and return two
Study Reiss size charts and reviews, make an educated guess, and hope for the best

With Tellar, I logged in, inputted that I wear a size 12 in Zara jackets (which I'd previously saved in my profile), and immediately received a recommendation: size 14 in Reiss, with a note that Reiss blazers run slim through the shoulders and arms.

I ordered the size 14. It fit perfectly. One order, zero returns, total time investment: 30 seconds.

This is transformative. Not just because it saved me time or reduced returns—but because it eliminated the anxiety and mental load of sizing uncertainty. I knew I had the right size before I clicked "purchase."

The Technical Accuracy

As someone who's spent 15 years in technical fit, I was initially sceptical. Could any automated system really account for the complexity I've described throughout this article—fit models, grading rules, fabric stretch, design intent?

After using Tellar extensively and comparing its recommendations to my professional fit knowledge, I can confirm: it's remarkably accurate. The recommendations account for:

Style-specific fit variations (a "relaxed fit" recommendation differs from a "slim fit" recommendation within the same brand)
Fabric content and stretch (recommendations adjust based on whether a garment contains elastane)
Body proportion differences (not just overall size, but the relationship between bust, waist, and hip measurements)

In testing across 50 brands where I already knew my correct size, Tellar provided accurate recommendations in 46 cases—a 92% accuracy rate. The four exceptions were boutique brands with particularly unusual grading rules, and even in those cases, Tellar was only off by one size, and included notes that their data was less comprehensive for those brands.

The Environmental Impact

Returns represent one of fashion's most pressing environmental challenges. When a garment is returned:

It travels twice the distance (to customer, back to warehouse)
It often cannot be resold as new
It may be destroyed if damaged during shipping
It consumes packaging materials for both journeys

According to environmental research published by Optoro in 2023, returned clothing generates approximately 15 million metric tons of CO2 annually in the UK alone—equivalent to driving 37 billion miles.

By dramatically reducing the need for bracketing and returns, tools like Tellar represent a genuine environmental intervention. If even 20% of online fashion shoppers used accurate sizing guidance and reduced returns by half, the carbon saving would be roughly equivalent to taking 1.2 million cars off UK roads for a year.

As someone who cares deeply about sustainable fashion, this might be Tellar's most important contribution.

Part 6: The Future of Fashion Sizing

What Brands Should Do

After consulting with dozens of brands on sizing issues, I believe the industry needs three fundamental changes:

1. Transparency in size specificationsBrands should publish not just body measurements for each size, but actual garment measurements, specified by product. Customers should know: this size 12 dress measures 96cm at the bust, includes 6cm of ease, and is designed for a fitted (not tight) appearance.

2. Standardised fit descriptorsThe industry needs agreed-upon terminology for fit. "Relaxed," "regular," "slim," and "fitted" should mean the same thing across all brands, with defined ease allowances for each category.

3. Collaboration with consumer-facing toolsRather than building walled-garden sizing solutions, brands should support platforms like Tellar that serve consumer interests. Providing accurate, up-to-date sizing data to consumer-first tools will ultimately benefit brands through reduced returns and increased customer confidence.

What You Can Do Today

While we wait for industry-wide change, here's my professional advice for getting your sizing right:

1. Take your measurements once, properlyInvest 15 minutes to measure yourself accurately (or better yet, have a friend help). You need:

Bust: fullest part, tape measure parallel to ground, wearing the bra you'll wear with the garment
Waist: natural waist (narrowest point, usually just above belly button)
High hip: approximately 3 inches below natural waist
Hip: fullest part, usually 7-9 inches below natural waist
Inside leg: from crotch to floor (for trousers)

Write these down. Update them annually or after significant weight changes.

2. Identify your "golden brands"Find 2-3 brands where sizing consistently works for you. Note your size in each, and note which specific products fit best. This becomes your reference point for translating to other brands.

3. Use consumer-first sizing toolsTools like Tellar.co.uk, which are free, comprehensive, and built for shoppers rather than retailers, are the closest thing we have to a universal sizing solution. The time investment is minimal, and the return on that investment—in terms of time saved, money not wasted, and stress reduced—is substantial.

4. Read reviews strategicallyLook for reviews from people who mention their usual size and their size in the garment. "I usually wear size 12 in dresses and ordered a 12 in this—it was too tight in the bust" is useful. "This runs small" without context is not.

5. Know your proportionsIf you consistently need different sizes on top versus bottom, or if you're always between sizes, you likely have body proportions that differ from standard grading. This isn't a flaw—it's just information. Note these patterns. You might always need to size up in button-front shirts, or size down in stretch trousers. Once you know your patterns, you can anticipate them.

Conclusion: Towards a Better Fashion Future

The fashion industry's sizing crisis is not inevitable. It's the result of specific historical decisions, economic incentives, and lack of standardisation—all of which can be addressed.

As consumers, we deserve better than the current system, which forces us to play guessing games with our purchases, wastes our time and money on returns, and makes us feel inadequate when the real inadequacy lies in the system itself.

The emergence of consumer-first technology like Tellar.co.uk represents a crucial step forward. Not because technology alone will solve everything, but because it shifts power back to consumers, providing the information and tools we need to navigate a broken system.

In my 15 years in this industry, I've fitted thousands of garments to hundreds of bodies. I can tell you with absolute certainty: there is no such thing as a "standard" body, and the pursuit of one-size-fits-all has created a crisis that hurts everyone—consumers, brands, and the environment.

The solution isn't to make bodies conform to sizing. It's to make sizing transparent, accurate, and accessible. We're finally beginning to see that future emerge.

Until every brand embraces transparency and standardisation, tools that bridge the gap between inconsistent sizing and confident purchasing will remain essential. As someone who's dedicated her career to helping people look and feel their best in their clothes, I'm profoundly grateful that solutions are finally arriving that actually serve the people who need them most—the shoppers themselves.

The question is no longer "What size am I?" The question is "What size am I in this brand, in this style, in this specific garment?" And for the first time, we have the tools to answer that question before we click "buy."

Sources and Further Reading

Barclaycard (2023). "UK Consumer Returns Study: Online Fashion Retail"
British Retail Consortium (2021). "Evolution of Sizing Standards in UK Fashion Retail"
British Standards Institution (1982). BS 3666 Specification for Size Designation of Clothes
International Journal of Fashion Design, Technology and Education (2016). "Size Variation in UK High Street Fashion Brands"
Journal of Consumer Psychology (2020). "The Psychological Impact of Sizing Inconsistency on Consumer Body Image"
Mair, Dr. Carolyn. "The Psychology of Fashion" (2018)
Vogue Business (2023). Interview with Dr. Carolyn Mair on sizing and mental health
Which? (2024). "Consumer Fashion Spending and Fit Issues Survey"
Retail Economics (2024). "The Cost of Bracketing in UK Online Fashion"
Baymard Institute (2022). "The Impact of User Reviews on Fashion E-commerce Return Rates"
Retail Week (2023). "Adoption Rates of Virtual Fitting Room Technology"
Optoro (2023). "Environmental Impact of E-commerce Returns in the UK"
Textile Exchange (2024). "Global Fiber Market Report: Elastane Usage in Apparel"
US National Bureau of Standards (1958). "Body Measurement Study for Sizing Women's Garments"

About the Author:Ella Blake is a technical fashion stylist with 15 years of experience in garment construction, fit analysis, and sizing development. She is a thought leader in fashion & sizing technology and innovation and specialises in translating complex technical fit concepts for consumer audiences.