Why Your 'Size' Keeps Changing From Brand to Brand
It's not in your head — the number on the label moves around. Here's what's actually going on, and how to stop letting it shake your confidence.
You buy your usual size from one shop and it fits. You order the exact same size from another and you can barely zip it up. A week later, a third brand sends you something so generous you're swimming in it. Same body, three different verdicts.
It's a uniquely modern frustration, and it has almost nothing to do with you.
Fashion sizing is famously inconsistent. The labels we treat as fixed — 8, 10, 12, S, M, L — are not based on a shared, regulated standard. Each brand builds its sizing around its own assumptions: who they think their customer is, what era of measurements they're working from, and how generous they want their fit to feel on the body.
That last point matters more than people realise. Vanity sizing — the slow practice of relabelling a garment with a smaller number so the customer feels good about themselves — has been quietly stretching what a 'size 10' means for decades. A size 10 today is closer to what would have been a 14 in the 1970s. And yet, fast fashion brands often keep their sizing tight to save fabric. Two opposing forces, pulling the same label in different directions.
The result is a system where your 'size' depends entirely on which shop you happen to be standing in. No wonder online shopping feels like a gamble.
The way out of it is quieter than the industry would like to admit: your actual body measurements. Centimetres don't lie, don't drift, and don't change their definition between brands. A 92cm bust is a 92cm bust whether you're buying from Oslo, London or Milan.
The trouble is, most of us don't really know our measurements. We know what size we usually buy. That's a very different thing.
This is the gap Idntfy is built to close. A two-minute body scan on your phone gives you accurate measurements you can carry from brand to brand — without measuring tape, without guesswork, and without ordering the same dress in three sizes just to be safe.
You don't have to learn the industry's logic. You just have to know your own body well enough to ignore it.