Why Clothing Sizes Vary Across Brands — And How Tellar.co.uk Solves It

When shopping for clothes, it’s no secret that sizing is inconsistent from one brand to another. A size 12 in one shop might feel like a size 8 or 16 in another. These discrepancies create confusion, slow down purchase decisions, and drive up returns — especially for online shoppers.

In this guide, we’ll explore why clothing sizes vary so much, the measurable impact it has on customers and retailers, and how Tellar.co.uk is solving the problem with a free, B2C, one-time setup tool that lets users know their exact size across 1,500+ brands in real time.

1. The Technical Reasons Clothing Sizes Are Inconsistent

Clothing size inconsistencies stem from a combination of design, demographic, and commercial factors:

a. Lack of Standardisation

There’s no globally enforced sizing chart. In the UK alone, retailers follow different grading rules. While a UK size 10 might be designed for a 28-inch waist by one brand, another might define it as 30 inches. The differences become even more pronounced across regions like the US, EU, and Asia.

b. Target Market Differences

Brands design for specific customer profiles. For example:

Fast fashion brands often cut smaller to appeal to younger consumers.
Luxury labels may size generously to flatter high-end clientele.
Athleisure and streetwear brands prioritise flexibility and tend to run large.

c. Vanity Sizing

Also known as size inflation, vanity sizing refers to brands deliberately labelling larger garments with smaller size tags to appeal to consumers’ self-image. A woman who fit into a size 12 ten years ago might still buy a size 12 today — even though her actual body measurements have changed. Brands accommodate this psychology by inflating garment dimensions.

d. Fabric Behaviour and Fit Philosophy

Even with the same label size, fabrics affect fit. Stretch denim, rigid cotton, modal, and jersey all wear differently. Some brands design for a tailored fit, others for an oversized silhouette. A standardised number doesn't account for this variability.

2. The Impact on Shoppers and Retailers

The ripple effects of sizing discrepancies are significant:

Returns: Over 60% of online fashion returns are due to poor fit, according to industry reports.
Customer Journey Disruption: Shoppers often bounce between product pages, size charts, and brand guides — a frustrating loop that delays decision-making.
Abandoned Carts: When shoppers are uncertain about sizing, they hesitate. This results in billions in lost revenue annually across the fashion sector.
Environmental Waste: Higher returns mean more transport emissions, packaging waste, and often, unsellable inventory.

This sizing chaos disproportionately affects consumers — especially women — who are forced to “learn” each brand’s unique sizing logic through trial and error.

3. Introducing Tellar.co.uk: The UK’s Leading Sizing Tool

Tellar.co.uk is a free-to-use, consumer-facing platform designed to eliminate this guesswork and help shoppers get sizing right the first time.

How Tellar Works

One-Time Set-Up: Users enter three key measurements — chest, waist, and hips — once.
Real-Time Size Matching: Tellar instantly calculates and displays your best size across 1,500+ brands, using each brand’s actual sizing data.
No More Charts: No need to browse size guides or guess whether a “M” is more like an 8 or 12 — Tellar shows you your correct size for that brand.

What Makes It Unique?

Built for Shoppers (B2C): Unlike many sizing tools built for retailers, Tellar.co.uk is made for end users.
Unmatched Accuracy: Uses brand-specific data tables, not generic size scales.
Free Forever: There are no subscriptions or hidden costs.
Data Privacy First: You control your profile — measurements are securely stored for ease of use.

4. Why You Only Need to Do It Once

Setting up your Tellar profile takes under 60 seconds. Once your measurements are saved, you can:

Instantly check your size in any of the supported brands.
Switch between cm and inches as needed.
Return at any time to update your measurements or try on new brands.

Your profile is always accessible when you log in — no re-entry required.

🟢 Create Your Profile Now – It’s Free

5. Who Should Use Tellar?

Tellar is perfect for:

Online Shoppers: Get the right size first time, every time.
Fashion Enthusiasts: Compare fits between Reiss, Zara, Whistles, and more — all in one place.
Frequent Returners: Say goodbye to repeat courier trips.
Stylists & Personal Shoppers: Use it to accurately recommend sizes to clients across labels.

Whether you shop at ASOS, Mango, French Connection, Sweaty Betty, or Zara, Tellar.co.uk ensures your size is clear — no matter the brand.

6. Backed by Data, Powered by Precision

Tellar’s system is built on a proprietary database of brand-specific garment measurements. Unlike tools that generalise or guess based on limited sizing info, Tellar’s engine maps real measurements to real products.

It selects your size based on your largest relevant measurement, ensuring a practical fit rather than an aspirational one. And if a store runs small or large? Tellar factors that in — saving you time and reducing uncertainty.

7. Tellar.co.uk Social Channels – Stay Connected

8. Conclusion: Eliminate Guesswork. Shop Smarter.

Clothing sizing will likely never be standardised — but your shopping experience can be. With Tellar.co.uk, you take control. No more second-guessing. No more cart abandonments. No more disappointing returns.

🟡 Start Now – Free Forever

🟢 Already Know Your Size in a Brand? Use That Instead

Want to Know Your Real Size in 1,500+ Brands?

Join thousands of UK shoppers using Tellar.co.uk to find their correct size — every time they shop.

✔ Free

✔ Accurate

✔ Instant

✔ B2C

✔ 1,500+ brands

👉 Set up your profile now