Understanding Luxury Fashion Sizing: Why It Runs Small and How to Get the Right Fit

In the world of fashion, luxury brands are revered for their craftsmanship, exclusivity, and design innovation. But when it comes to sizing, they’re also infamous for being inconsistent—often running significantly smaller than high street or mass-market labels. If you’ve ever tried on your usual size in a designer boutique only to find it impossibly tight, you’re not imagining things.

This article explores why luxury sizing tends to run small, how it compares across regions and brands, and how platforms like Tellar.co.uk are using data to eliminate guesswork from the equation.

1. The Origins of Luxury Sizing Standards

a. European Size Legacy

Many luxury houses originate in France, Italy, or Japan, and their sizing systems reflect traditional regional metrics. These were established decades ago and have evolved little since. For example:

French sizing typically uses a base-36 system (e.g., 36, 38, 40), where a French 38 roughly equates to a UK 10—but often fits more like a UK 8.
Italian sizing runs even smaller. An IT 42 may claim to match a UK 10 but often mirrors a high street UK 8 in cut and fit.
Japanese sizing is based on a more petite national average and tends to run significantly smaller across bust, hip and length dimensions.

Most luxury brands have retained these original scales for consistency across global markets—even as average body measurements have increased worldwide.

2. Designer Fit Models and Sample Sizing

Luxury garments are typically developed using fit models who are slimmer, taller, and have more symmetrical proportions than the average consumer. These models usually wear a base size that becomes the reference for grading other sizes.

For example:

A French luxury brand might base all fits on a EU 36 with a bust 84 cm, waist 62 cm, hips 88 cm.
As the size scales up, adjustments are made linearly—but they often don’t account for real-world body variations, like broader shoulders, fuller busts, or shorter torsos.

Sample Size Bias

Luxury collections are often produced first in a sample size (usually 36 or 38 EU) for runway or press purposes. Since collections are only graded after the sample is approved, any small-scale fitting issue can get amplified across the size range.

3. Exclusivity and Brand Positioning

Luxury fashion is as much about perception as product. A smaller size scale subtly reinforces:

Exclusivity: Fewer people “fit” the brand, increasing aspirational value.
Aesthetic control: Designs are meant to drape and fall in very specific ways, often on straight frames.
Cultural capital: Certain silhouettes or body types become “standard” within luxury spaces, setting unrealistic expectations for fit.

This is why luxury fashion often eschews inclusive sizing entirely, rarely offering sizes beyond EU 44 (UK 16) and often stopping at EU 42 (UK 14) in mainlines.

4. Fabric Composition and Fit Tolerance

Luxury pieces are constructed from natural, high-quality fibres—like silk, virgin wool, cashmere, and crepe de chine. These materials:

Do not stretch the way synthetic blends do
Offer limited forgiveness if the size isn’t exact
Are cut with extreme precision to maintain structure and silhouette

For example:

A structured Dior blazer with padded shoulders and silk lining will not accommodate sizing error.
A Chanel boucle dress is designed to skim the body precisely—not cling or stretch.

This further compounds the risk of ordering your usual high street size and receiving a garment that’s unwearably small.

5. Brand-Specific Sizing Differences

Even among luxury labels, fit varies drastically. Here’s how popular luxury brands compare to typical UK high street sizing:

Brand	Sizing Notes
Dior	French sizing, highly tailored; jackets and dresses tend to run 1-2 sizes small.
Saint Laurent	Very slim in shoulders and hips; trousers often cut for straight body types.
Isabel Marant	Slim-fit across most categories, especially trousers and blouses.
Celine	Modern minimalism but very fitted tailoring; jackets can run two sizes small.
Dolce & Gabbana	Italian sizing; highly structured bust and waist, especially in dresses.
Jacquemus	Youth-focused; cut small in both width and length.
The Row	Oversized aesthetics but narrow sleeves and shoulder seams.
Prada	Narrow cuts and high armholes; best suited to petite builds.

6. The Sizing Gap: Real vs Labelled

If you're a UK 10 (M) in Zara, this is how your “real size” might shift across luxury brands:

High Street Brand	Luxury Equivalent
Zara (UK 10, M)	Dior EU 42 (UK 12–14)
COS (UK 10, M)	Celine EU 40 or 42
Reiss (UK 10, M)	Dolce & Gabbana IT 44
& Other Stories (M)	Isabel Marant 42

Even within a single luxury brand, you may wear different sizes across product types (e.g., a blouse vs a tailored blazer).

7. How Tellar.co.uk Solves the Sizing Problem

Rather than relying on generic charts, Tellar.co.uk matches your actual body measurements or known brand size to a database of over 1,500+ brands, including luxury houses. This means:

If you’re a UK 10 in Reiss, Tellar can tell you what size you’ll need in Balmain or Valentino.
If you’ve measured your bust, waist and hips, Tellar will return the closest matching size in luxury brands based on real garment data—not just what’s on the label.

How It Works:

Visit Tellar.co.uk
Create your free profile
Choose between entering body measurements or selecting a brand and size you already wear
Instantly get size recommendations for luxury, high street and designer brands

It’s 100% free—and it means you’ll never waste money on the wrong size again.

8. How to Shop Smarter for Luxury Pieces

When investing in high-end fashion, precision matters. Use these technical tips:

Always check the fabric composition: If there’s no stretch, you’ll need a more forgiving cut or exact measurements.
Know the origin of the sizing: French and Italian sizes will usually need you to size up.
Compare measurements in CM or Inches: Don't rely on "M" or "L"—know your bust, waist and hip in cm/inches.
Use Tellar.co.uk for exact brand conversion: Stop guessing and start measuring.
➡️ Try the size lookup tool now

9. Stay Informed

Follow Tellar.co.uk for more brand-specific guides, luxury fit insights, and smart shopping tools:

Instagram: @Tellarsizing
Pinterest: TellarUK
Twitter (X): @TellarSizing
Facebook: TellarSizing

Final Word

Luxury fashion demands attention to detail—and sizing is one of the most overlooked. As brands maintain regional standards, exclusive aesthetics and rigid silhouettes, the gap between what’s on the label and what fits your body continues to grow.

But with Tellar.co.uk, it doesn’t have to be guesswork anymore. Whether you're shopping Celine, Saint Laurent or Dior, our real-time fit technology makes luxury sizing accessible, accurate and stress-free.

Find your size in 1,500+ brands real-time. It’s free & easy.

➡️ Start now at Tellar.co.uk