How to read womenswear sizes (cross-house)

The tells — 7, sourced

1. 01

   The rule above all: the tag is a CLAIM, not a fit. Archive womenswear crosses four sizing systems and three decades of drift — measurements decide, the tag only suggests. Ask for pit-to-pit, waist laid flat, shoulder seam-to-seam, and back length before weighting any number on the label.

2. 02

   The conversion ladder (standard RTW equivalences — brands vary, use as orientation): IT 36 ≈ FR 32 ≈ UK 4 ≈ US 0 · IT 38 ≈ FR 34 ≈ UK 6 ≈ US 2 · IT 40 ≈ FR 36 ≈ UK 8 ≈ US 4 · IT 42 ≈ FR 38 ≈ UK 10 ≈ US 6 · IT 44 ≈ FR 40 ≈ UK 12 ≈ US 8 · IT 46 ≈ FR 42 ≈ UK 14 ≈ US 10. Rules of thumb: FR = IT − 4; US = UK − 4.

3. 03

   THE '38' TRAP — the single costliest womenswear misread: a FRENCH 38 (≈ US 6) and an ITALIAN 38 (≈ US 2) are two different bodies wearing the same number. French houses (Margiela's line 1, the Belgian houses, old Céline) tag FR; Italian-made (Prada, Miu Miu, Gucci) tag IT. Identify the house's tagging country BEFORE reading the number — a seller's 'size 38' means nothing alone.

4. 04

   Japanese sizing is its own system: JP 7 ≈ US 2, JP 9 ≈ US 4–6, JP 11 ≈ US 8 — but the Japanese archive houses mostly avoid it: CDG womenswear runs S/M/L (or nothing), and Yohji mainline moved from S/M/L to numeric 1/2/3/4 at SS2000 (a dating boundary — see the Yohji protocol). Japanese womenswear cuts SHORTER in sleeve and torso at the same nominal size; the oversize Yohji/CDG silhouette is design, not a size up.

5. 05

   Vanity drift dates the tag: sizing has inflated for decades, so a 1990s US 8 fits roughly like a modern US 4–6, and a 1980s tag runs smaller still. On vintage womenswear, assume the garment is 1–2 modern sizes smaller than its tag claims — another reason measurements rule.

6. 06

   Cross-references already in the house protocols: Dior Homme's women's-cut line is tagged F (Femme, 'petite taille', sizes like 38/40) — not a mislabel (see the Hedi protocol); Margiela's Italian 74/78 tags are the AW2000 XXL concept, a feature not a size (see the Margiela protocol); Helmut Lang runs small across the board — 'when in doubt, size up.'

7. 07

   The hunting move this unlocks: NEVER filter a marketplace by tag size alone. Mistagged and cross-system listings are where archive womenswear deals live — a 'size 6' search misses the IT 42 grail tagged '42'. Search by the piece and the construction language, then read measurements against your own — the tag is the last thing you check, not the first.

Two sources or it ships as rumor. Where a tell is collector-lore rather than a museum fact, the tell says so — weight it with construction and provenance, never alone.