Why is a 'size 8' different in every store?

Because size is not a standardized unit. Each brand picks a target body measurement for their 'size 8' based on their customer demographic. Plus, sizing has drifted downward over 60 years (vanity sizing) in the US. The only reliable measure is inches or centimeters, which every brand publishes in their size chart. Always measure yourself once, then compare to the brand's numbers, not to the label size.

What's 'vanity sizing' and why does it exist?

The industry practice of labeling a garment with a smaller size number than the measurement would suggest. A 28-inch waist was 'size 8' in 1970; today the same 28 inches is labeled 'size 4' by some brands. Brands shifted numbers down because customers feel better about smaller numbers. The effect is cumulative — each decade of drift adds one or two sizes. Objective measurements in inches or centimeters are immune.

Italian sizing vs EU sizing — what's the difference?

Italian sizes tend to run one size smaller than the general European scale. An IT 42 women's dress is roughly EU 40 or US 8. Italian brands (Gucci, Prada, Armani) usually print both IT and EU sizes on tags. When in doubt, use the cm/in body measurement chart.

Clothing Size Converter — Unit Converter Hub

Introduction

Clothing size conversion is a rough guide at best. Vanity sizing (where brands shift the numbering over decades to flatter customers) means a modern US size 8 is roughly equivalent to a 1990 US size 10, which was a 1970 size 12. European sizing is more stable but still varies by brand. For anything that matters, check the brand's size chart in inches or centimeters and measure yourself against it.

Why clothing size units exist and how they diverged

Vanity sizing has been a one-way drift in US women's clothing since the 1950s. The same body measurement that was 'size 14' in 1958 is 'size 8' today. Levi's 501 jeans are famously consistent — but most US brands are not. EU sizing starts from body measurements (EU 38 = 92 cm bust) but also drifts slowly.

Men's clothing is usually more consistent because it's measured directly (34-inch waist, 32-inch inseam on jeans; 15.5-inch neck on dress shirts). Women's clothing uses the arbitrary number system — which is why it needs a conversion calculator at all.

How to convert clothing size

Common US/UK/EU women's mapping: US 4 = UK 8 = EU 36. US 6 = UK 10 = EU 38. US 8 = UK 12 = EU 40. US 10 = UK 14 = EU 42. These are rough. Italian sizing tends to run one size smaller than the general EU scale (an Italian 42 = EU 40 = US 8).

For men's dress shirts: neck + sleeve length in inches. A 15.5 / 34 shirt fits a 15.5-inch neck and a 34-inch sleeve. For suits: chest measurement in inches (US/UK) or centimeters (EU); EU is usually chest in cm divided by 2 (100 cm chest = EU 50).

Units supported by this clothing size calculator

US
UK
EU
Italy
France

Common clothing size conversion mistakes

Italian vs general EU. Italian clothing runs small by one size. 'IT 42' is usually EU 40, which is US 8.
Vanity sizing across decades. A modern US 8 is a 1975 US 14. Vintage shopping needs the actual inches, not the number on the label.
UK vs US. UK sizes are 4 higher than US (US 8 = UK 12). The easy mnemonic: 'Plus 4 for the UK.'
Body measurement vs garment measurement. Brands sometimes list 'bust 36 inches' as body measurement; others as garment measurement (the actual garment has 2-4 inches of ease). Always check which.
Stretch fabric tolerance. Leggings and knit tops are forgiving; woven blouses and tailored pants are not. Size charts are more reliable for non-stretch fabrics.

Real-world clothing size examples

US 6 (Women) ≈ UK 10 ≈ EU 38 ≈ IT 40 ≈ FR 38.
Body measurements for US 8: bust ~36 in (91 cm), waist ~28 in (71 cm), hips ~38 in (97 cm).
Men's dress shirt '16/34' = 16-inch neck × 34-inch sleeve.
Men's suit 42R = 42-inch chest, regular length.
Men's 32x32 jeans = 32-inch waist × 32-inch inseam.
EU 50 suit = 100 cm chest = US 40.

Tips for accurate clothing size conversion

Measure yourself: chest/bust (around fullest part), waist (narrowest point above hips), hips (fullest point below waist), inseam (inner leg, crotch to floor).
Use the brand's chart, not a generic one. Every brand's 'size 8' is different.
For international shopping, always check returns policy first. Sizing surprises are the #1 return reason.

Clothing Size Converter

1 US across units