A few years back, I thought I’d stumbled upon the fashion holy grail – a flattering pair of jeans . When they started to disintegrate a few months ago, I thought I’d head back to buy the same style in the same size. Simple, right? But when I tried them on, I felt like I’d fallen into a funhouse mirror.

The “same” size jeans had shrunk (yes, new jeans are tighter than well-worn ones, but this was extreme). When I returned them, the staffer behind the till told me she’d had the same problem – and that she now goes two sizes up as a default. It’s not just us.

Head over to social media platforms like Instagram and TikTok and you’ll find a whole load of videos of disgruntled shoppers complaining about veering from a small to large in different brands – or sometimes having to switch sizes within the same store . The problem seems especially bad when it comes to online shopping: ordering multiple sizes, crossing your fingers and hoping that one might fit has become commonplace. Womenswear seems particularly hard to navigate, though that’s not to say that men aren’t struggling with the same problem too.

Anecdotally at least, I certainly don’t remember having to test out multiple sizes quite so often when I was in my early twenties, about a decade ago. So why has the blight of erratic sizing become increasingly pronounced in recent years? Standard sizing is a relatively new phenomenon. It began to emerge in the 19th century, when armies had to produce milit.