Who Decides What Size You Are?

Fashion sizing is arbitrary, inconsistent, and historically rooted in military data from the 1940s. The system is broken. Why hasn't anyone fixed it?

A medium at Zara is not a medium at Uniqlo is not a medium at Nike is not a medium at Cos. You already know this. What you might not know is why: the modern sizing system traces its origins to a 1941 study commissioned by the U.S. Department of Agriculture, which measured roughly 15,000 women — overwhelmingly white, disproportionately young — and used the data to create a standardized sizing chart. That chart, with minor modifications, is still the conceptual foundation for how most Western brands size their garments. It was flawed from the start, and everything built on it has inherited those flaws.

The problem is simultaneously technical and political. On the technical side, human bodies vary along dozens of dimensions that a simple size label cannot capture. A single measurement like chest circumference tells you almost nothing about shoulder width, torso length, or the distribution of tissue. The fashion industry has always known this — couture exists precisely because standardized sizing cannot accommodate individual bodies. But standardization is what makes mass production profitable, so the industry chose scale over fit and then marketed aspiration to cover the gap.

Several companies have attempted to solve this with technology. Startups like Bold Metrics and 3DLook use AI-powered body scanning to generate custom size recommendations. The results are incrementally better but still constrained by the underlying garment construction. A more precise recommendation doesn't help if the garment itself was cut to a standard that doesn't match your proportions. The deeper fix would require brands to rethink their entire production process: more size ranges, more body data, more variation in pattern grading. That costs money, and the industry's incentive structure rewards selling to the most people at the lowest production complexity.

In Seoul, a different approach is emerging. A wave of Korean independent brands have started offering garments in adjustable formats: drawstring waists, modular panels, wrap constructions that accommodate a range of bodies without requiring a size chart at all. This isn't entirely new — traditional garments in many cultures, from the Japanese kimono to the West African wrapper, have always been designed for adaptability rather than fixed sizing. What's notable is that contemporary designers are returning to this principle not out of nostalgia but out of practical frustration with the limitations of Western sizing conventions.

The most honest thing to say about fashion sizing in 2026 is that it remains a system designed for manufacturing convenience, not for the people wearing the clothes. The data it's built on is outdated, racially skewed, and geographically narrow. The technology to improve it exists but remains underdeployed because the cost of implementation exceeds the perceived cost of customer dissatisfaction. Until that calculus shifts, you'll keep standing in fitting rooms, holding two garments labeled the same size that fit completely differently. Nothing went wrong. The system is working exactly as it was designed. It just wasn't designed for you.

• WordsSHEPHERD
• PublishedMarch 20, 2026 — TINCT Fashion
• Reading time7 min