How designer sizing differs between French, Italian, and US sizes

A size number is a label in a local habit. It is not a body measurement, and the same number does not mean the same fit from one house to another.

Three habits, not one scale

United States ready-to-wear often uses even numbers such as 0, 2, 4, 6, 8, and sometimes 00. France and much of continental Europe use a higher band, commonly 34, 36, 38, 40, and upward. Italy uses a numbered band in a similar range. Those Italian numbers are not automatically the same garments as the French numbers that look alike.

United Kingdom dress sizes are another series again, often sitting a few steps away from the US number used for a similar body. Shoe sizes split the same way: a European shoe size, a US shoe size, and a UK shoe size are different numbers for a similar foot. Width may be marked, or it may not.

Shops publish conversion charts. Charts from different shops disagree, and a chart is not the pattern the designer used. This guide does not print a conversion table, because a table would look more certain than the cutting room is.

One house can use two systems

On Rabanne’s fashion site, many dresses are offered in numbered sizes such as 34 through 46, while some knit pieces are offered in letter sizes such as XS through XL, and some shoes in a 35 to 41 range. Letter sizes and numbered sizes on the same site are not two names for one measurement. Read the label that belongs to that product.

Christian Louboutin and other Paris shoe houses sell primarily on European shoe sizes. Use the size guide on that brand’s site, including any note about width. A US shoe size you wear in another maker is only a place to start.

Why two “38” dresses fit differently

Designer houses cut to their own block. Ease, shoulder width, armhole, and intended undergarment change the fit of two garments that share a number. Evening clothes are often cut closer to the body than coats. A sample size used on a runway is not a promise about the size that will be stocked.

Pre-owned clothes add wear. Waistbands relax, shoes stretch, and knit grows. The number sewn into the garment records how it was labeled when it was made, not how it measures today.

What to compare

For a new piece, open the size guide on the brand’s own site and follow that guide. For a pre-owned piece, ask the seller for flat measurements: bust or chest, waist, hip, shoulder seam to shoulder seam, sleeve length, and the garment’s length. For shoes, ask for the insole length in centimeters and, if they can, the width across the ball of the foot.

Measure a garment you already wear and like, laid flat, the same way. Compare centimeters to centimeters. If the listing has no measurements and the seller will not provide them, you are buying from the number alone.

Questions about the guide: sales@sco-enterprises.com.