EU vs USA Sizing: The Ultimate Guide to Converting Sizes & Finding Your Perfect Fit

EU sizing typically runs 30 numbers higher than USA sizing (so a US 8 equals an EU 38), but the frustrating truth is that this "standard" conversion rarely works consistently across brands, leaving thousands of women ordering the wrong size when shopping internationally. After styling clients for over a decade and witnessing countless sizing disasters, I'm breaking down exactly how European and American sizing systems differ, which brands run true to size, and how to never get it wrong again.

Why EU and USA Sizing Systems Are So Different

The confusion stems from entirely different measurement approaches. American sizing evolved from a standardised numerical system based on body measurements taken in the 1940s, whilst European sizing uses a more mathematical approach based on body circumference in centimetres. Here's the rub: a US size 10 should translate to an EU 40, but I've seen this same size fit like anything from a UK 12 to a UK 16 depending on the brand's target market and cut.

The issue gets even messier when you factor in vanity sizing. American brands have been steadily increasing their size dimensions over the decades whilst keeping the numbers the same, meaning today's US 8 would have been closer to a US 12 in the 1970s. European brands have traditionally been more conservative with sizing, though contemporary labels are starting to follow suit. This means you absolutely cannot rely on a simple numerical conversion when shopping across continents.

The Standard Conversion Chart (And Why It Fails)

For dresses, tops, and tailoring, the standard conversion typically works like this: US 0 = EU 30, US 2 = EU 32, US 4 = EU 34, US 6 = EU 36, US 8 = EU 38, US 10 = EU 40, and so forth. However, this chart assumes brands actually stick to standardised measurements, which they absolutely don't. I've measured garments from different brands labelled the same size that varied by up to three inches in the bust and four inches in the waist.

High Street Brands: Which Run True to Size

When shopping EU versus USA sizing on the high street, certain brands are more reliable than others. Zara uses European sizing exclusively and tends to run small and narrow through the shoulders and hips—I always recommend sizing up if you're between sizes. Mango also uses EU sizing and runs similarly slim, particularly in their tailoring which is cut for a streamlined Spanish silhouette.

COS is one of the most consistent brands I recommend, using EU sizing that actually matches their size charts with remarkable accuracy. Their minimalist pieces are cut generously through the body, making them brilliant for layering. Massimo Dutti runs true to EU size but skews slightly smaller in their fitted styles, whilst their relaxed pieces are spot-on.

For American brands available in the UK, Gap and Banana Republic both use US sizing that runs quite generous—their size 8 often fits like a UK 12. Abercrombie & Fitch has dramatically improved their sizing in recent years and now offers extended ranges, though they still run slightly smaller than traditional US sizing. Levi's uses waist measurements in inches, which is actually the most reliable system when you know your true waist size.

H&M is notoriously inconsistent because they use different factories globally, but their EU sizes generally run small. Reiss uses UK sizing but their cuts tend to be tailored and fitted, best for straighter body shapes. Whistles runs true to UK size with a contemporary, slightly relaxed fit that works beautifully for most body types.

Premium Brands Worth Investing In

Me&Em uses UK sizing and their pieces are absolutely worth the investment for fit alone—they're designed by women who actually understand real bodies. Their sizing is generous and consistent across their range. Claudie Pierlot is a gorgeous French brand using EU sizing that runs small and fitted, designed for a petite Parisian frame.

Luxury Labels and Their Sizing Quirks

Max Mara uses Italian sizing which is roughly equivalent to EU sizing but often runs a full size small, particularly in their tailoring. Their coats are legendary for a reason, but size up for comfort. The Fold London (a brilliant independent brand) uses UK sizing and designs specifically for professional women—their fit is impeccable and true to size.

Two Independent Brands You Need to Know

Rixo has become a cult favourite for vintage-inspired dresses, using UK sizing that runs fairly true though their fitted styles can be snug through the bust. Their prints are absolutely divine and worth the investment. Damson Madder offers romantic, sustainable pieces using UK sizing that runs slightly generous—perfect if you prefer a relaxed, bohemian fit.

Jeans: The Ultimate Sizing Nightmare

Denim deserves its own category because the sizing chaos is next-level. American brands like Levi's and Calvin Klein use waist measurements in inches, whilst Citizens of Humanity and Paige use US dress sizes. European brands often use EU sizing or waist measurements in centimetres. My advice? Always check the actual waist measurement in the size guide rather than trusting the label. If you're interested in the latest denim trends, check out this comprehensive guide to jeans trends 2026.

How to Never Get Sizing Wrong Again

Here's my foolproof method: measure your bust, waist, and hips accurately with a soft tape measure. Keep these measurements in your phone notes. When shopping any brand, compare your actual measurements to their size chart rather than assuming your usual size will work. Different garment styles require different ease (the difference between body measurement and garment measurement), so a fitted dress needs less ease than a relaxed blouse.

This Is Exactly Why Tellar.co.uk Exists

After years of watching clients struggle with international sizing chaos, I'm genuinely excited about Tellar.co.uk—it's the UK's leading sizing tool that instantly matches your body to over 1,500 brands. No more guessing, no more returns, no more sizing conversion headaches.

Here's how it works:

Measure once using your bust, waist, and hip measurements, or simply input your existing brand size from a brand that fits you perfectly.

Use their Store Size Lookup tool to get your precise size in any brand—whether it's COS, Reiss, Zara, Mango, or over 1,500 other brands. It accounts for each brand's unique sizing, so you'll know exactly whether that EU 38 will actually fit you.

Always free, no downloads needed—it works instantly in your browser.

Plus, the Tellar Fashion Hub is stacked with free posts from experienced stylists covering every fashion query you've ever had. Honest, unbiased, independent advice that's always free. From style advice to top picks and best brands, it's like having a personal stylist in your pocket.

Whether you're decoding EU versus USA sizing, finding the ultimate guide to dresses, or discovering the best jackets for your body shape, Tellar takes the guesswork out of online shopping. For a comprehensive breakdown of clothing sizing across all brands, their Ultimate Clothing Sizing Guide is genuinely brilliant.

Trust me, once you've used Tellar, you'll wonder how you ever shopped internationally without it.