Is your clothes size different in every high street shop? This is why

Are you a size ‘small’ in one shop and a ‘large’ in another? You’re not alone. Katie Rosseinsky explores why it’s so hard to find clothes that fit these days

Measuring up: finding clothes in the correct size seems to be getting harder (Getty/iStock)

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 military uniforms on a major scale, but women’s fashion was slower to catch up. The rise of mass production and the popularity of clothing catalogues in the first half of the 20th century, though, made this a more pressing concern.

In 1939, the US government commissioned a study that would collect the measurements of thousands of women in order to compile a sizing system (however, Ruth O’Brien, who headed up the survey, would only use data from American-born white women, so the findings were far from being truly representative). In 1958, the US’s National Institute of Standards and Technology introduced a system of even numbers from 8 to 38 to cover a range of sizes, and companies were told to design their clothes in line with this. However, this system was later made voluntary, and had been ditched by the early Eighties.

On this side of the Atlantic, a similar pattern emerged. The UK’s first major sizing survey for women took place in 1952, and the findings were then used to inform clothing sizes. However the survey participants were mostly young, white women, so, as in the United States, the results were inevitably skewed. A few decades later, in the 1980s, the British Office of Standardisation issued another set of garment sizes, known as BS 3666, based on that previous data. These guidelines weren’t compulsory, however, so manufacturers and retailers could essentially decide upon their own rules if they wished.

Nowadays, each brand will have a “base” or “sample” size that they use to create their design prototypes – but the dimensions for this “sample” won’t necessarily line up with those used by others. “You could have three different brands and their base size 10 might not be the same measurements,” says Victoria Jenkins, garment technologist and founder of the adaptive clothing brand Unhidden. The process of making the sample size design bigger or smaller is known as grading, and this might create further disparity too, because “not all brands have the same difference between sizes,” she adds.

Ego boost: some retailers resort to vanity sizing to encourage us to buy clothes (Getty)

With all this potential for variation, it’s easy to see why the size 12 T-shirt that you pick up from one high street store might feel skintight, while the “same” size garment from the shop next door might hang off your shoulders. But there are also other factors at play. Women are bombarded with messages suggesting that smaller sizes are more desirable – and that thinner is better. Various studies have found that shoppers are more likely to buy clothes when the number on the label is lower, because of the resulting ego boost.

In order to capitalise on this, some brands have inflated their sizes so that customers feel better (and spend more), a phenomenon known as vanity sizing. So, although the stats show that people have got larger, sizes have been relabelled so as to appear smaller. In 2015, American data showed that a present-day dress in a US size 8 (a UK size 12) was roughly equivalent to a US size 16 (UK size 20) item from 1958. A US size 8 dress from that era was so tiny, it doesn’t even have a modern equivalent. It’s not just an issue for womenswear – some men’s brands will understate the waist size on a pair of trousers, for example.

To confuse matters further, you’ll also find clothing companies that do the exact opposite, scaling their sizes down. These are often fancier, higher-end brands that aren’t chasing after mainstream appeal, or those aimed at a younger, more fashion-forward market. “Not only do they not make very large sizes, but the differences between them tend to be smaller, and their base size would be smaller,” Richards says. This is known as exclusivity sizing: “When a brand doesn’t want people of a certain size to be wearing their clothes. It’s done on purpose.” Sizing, it seems, is bound up in how a fashion label views itself, and how it wants to be seen by customers.

A lot of brands are working to tighter time frames and this puts pressure on the fit process

Alex Standley, personal stylist

And, if it seems like trying on clothing has become even more hit-and-miss recently, the issue might have been exacerbated by fast fashion and the way it’s sped up the industry. Some companies turn garments around in just a fortnight. When “a lot of brands [are] working to tighter time frames from concept through to delivery in-store, this puts pressure on the fit process”, says personal stylist Alex Standley, who spent 15 years as a fashion buyer. These companies may “also cut corners and potentially accept bigger variations in sizing from factories, in order to get clothing out to their stores quicker”.

In order to keep producing at such a rapid rate, they will probably be dealing with “a whole range of suppliers from all over the world”, says Lynne Hugill, principal lecturer in international fashion at Teesside University. “If they’re turning around clothing quickly, they’re not buying from one factory, but from lots of factories.” Each may have a different approach to sizing, and varying levels of tolerance for any divergence. “They’re producing these garments so quickly and at cheap prices, that the quality checking is not there,” she notes.

Blame: when clothes don’t fit, we often think we are the problem, not the garments (Getty/iStock)

This focus on speed over quality control goes some way to explain why two separate styles of, say, trousers from the same store in the same size might fit very differently. When Standley worked at Marks & Spencer, the company had “a very thorough fit process where they fit on both size 12 and size 18 fit models” who were “within a set of measurements to keep consistency of sizing”. But, she notes, “many ultra-fast fashion brands don’t have a robust fit process in place, and often aren’t even fitting on a human body to save time”. Instead, they may use a mannequin rather than a real person (“If they can’t tell you if it’s uncomfortable, they probably shouldn’t be used for fitting,” Richards says).

Despite the fact that our clothes might have been sized on a plastic person rather than a living, breathing one, we tend to assume that we are the problem, rather than the garment itself. Trying on clothes in what should be our size, only for them to barely fit over one of our limbs, is a uniquely dispiriting experience. “You buy something in a shop that you normally buy from, and then suddenly it’s too tight,” Richards says. “You [think], instantly, ‘I’ve gained weight’. You don’t think ‘Oh, the garment is too small.’” Standley agrees: “We internalise feelings of shame or frustration and blame ourselves for being too big, when often the problem is with the retailer and not with ourselves,” she says. “I always encourage my clients to not attach their self-worth to the clothing label size, as it means absolutely nothing, especially with the amount of discrepancy across the high street and online.”

Erratic sizing isn’t just bad for our self-esteem – it’s damaging for the environment too. It’s estimated that up to half of the clothes bought online are returned; a 2023 survey from the British Fashion Council found that incorrect sizing or fit was the reason behind 93 per cent of returns. The extra journeys required to transport unwanted products back to the retailer mean a higher carbon footprint and, in 2022, fashion returns accounted for an estimated 750,000 tonnes of CO2 in the UK alone. Some big online stores have recently introduced returns charges for repeat offenders – only for shoppers to point out their ongoing struggles with sizing.

Waste: some returned items will end up in landfill (Getty)

Then there’s the fact that some retailers don’t bother to resell returned items; they go straight into landfill. Standley points to research done by organisations such as the Changing Markets Foundation. “[It] suggests that many fast-fashion retailers are destroying stock that is returned to them, rather than putting it back into circulation, due to the rising costs of handling returns,” she says. “Many customers are not aware of the impact of trying multiple sizes when ordering online.”

So what can actually be done? You might think that there’s an obvious answer – rolling out a proper standardised system for all clothing brands. But – spoiler alert – that seems pretty unlikely. “I would love to see standardised sizing across menswear and womenswear,” Richards says. “But I don’t know how it could be enforced.”

I would love to see standardised sizing across menswear and womenswear. But I don’t know how it could be enforced

Victoria Richards, Unhidden

She points out that brands might fear that “it [would] hit their profits if they got caught out doing vanity or exclusivity sizing” or that it would “prove that they’ve not got any kind of quality assurance in place”. Plus, there’s the fact that a “standard” body doesn’t really exist: two people might wear the same dress size, but have a totally different shape. “With the best will in the world, it is extremely difficult for retailers to cater to every body shape on the spectrum within one size,” Standley says. “They have to go for the ‘average’ shape and proportions.”

The rise of AI means that digital “fit rooms” – where shoppers can input their measurements and fit preferences, then receive guidance about which size to choose, or even see a garment on a realistic avatar – are now “much easier to create”, Hugill says (although she notes that they’re “not quite mainstream yet” because running them “does add a cost onto the garment”). And some retailers, she adds, have started collecting “fit analytics” based on “shoppers’ preferences, sales and returns” and other data, which allows them to recommend sizes to online customers.

Richards, meanwhile, describes the issue as “a mountain to overcome”, but thinks that more clarity about what labels actually mean would also help. “I do think brands have a responsibility to be a lot more transparent,” she says. “It shouldn’t hurt them to publish what their garments actually measure” or to say “Look, this is what we’re calling a size 10… That doesn’t mean that you’re not a size 10 [overall]. It’s just that’s what our 10 is.” Dismantling our own psychological attachment to the number on a label, though, might be a more convoluted process.