Shoe Size Converter
Convert between US, UK, EU and kids' shoe sizes, anchored to actual foot length rather than a single shaky formula. Measure your foot once, and every system updates together.
Measure heel to longest toe, standing, at the end of the day — see the guide below.
Sizes are a close estimate based on standard charts — fit still varies by brand and last. Click any row to load that size.
How to Convert a Shoe Size
Features
One Foot, Six Different Numbers
Measure a single foot and you can honestly describe it as a US 9, a UK 8, and an EU 42.5 — three completely different-looking numbers, none of them wrong. Each sizing system counts up from its own starting point using its own step size, shaped by a completely different national shoemaking tradition, and none of the three was ever designed with the others in mind. That is the whole reason shoe size conversion exists as a genuine problem rather than a trivia footnote: order a European sneaker brand without converting first, and there is a real chance the number that feels natural to type is off by more than a full size. This tool works the problem from the one number that never changes no matter which country's chart you're reading — the actual length of your foot — and derives every system from that single measurement instead of trying to convert one shaky label into another. Even Mondopoint, the length-based system used across much of Asia and in technical and military footwear, sidesteps the whole labelling mess by simply printing the foot length in millimetres directly on the shoe — arguably the most honest of any system covered here, even if it never caught on for everyday consumer retail the way the labelled systems did.
Why Continental Europe Counts in Two-Thirds of a Centimetre
EU sizes run in a completely different unit called the Paris point, defined as exactly two-thirds of a centimetre — about 6.67 mm per whole size, a French shoemaking convention that spread across the continent as those manufacturing standards became the regional norm. UK and US sizing trace back instead to the old English barleycorn, a third of an inch, about 8.47 mm per size — a noticeably bigger step than the Paris point, which is exactly why EU size numbers climb so much higher than UK or US numbers for an identical foot: smaller steps simply need more of them to cover the same distance. Neither system is more precise than the other; they're just two different historical rulers that never got reconciled into one international standard, in the same way length itself once had its own competing local units before the metre took over. Even within the barleycorn family the split isn't perfectly clean: US men's sizes and UK sizes sit about half a size apart, while US women's and UK women's sizes typically run closer to two full sizes apart — a quirk that says more about how the two countries' sizing conventions drifted independently through the 20th century than about any consistent underlying logic connecting them.
An Online Shopper, a Parent, and a Traveller
Someone ordering trainers from a UK retailer sees a size 8 listed and needs to know instantly whether that's their familiar US 9 before checkout closes — a direct lookup rather than a mental approximation avoids an expensive returns process for a shoe that never should have shipped in the first place. A parent buying their child's first pair of proper sneakers runs straight into the confusing 13C-to-1Y jump in US kids sizing, which looks like a chart error the first time anyone encounters it but is actually two historically separate size ranges stitched together — this tool treats the whole kids range as one continuous foot-length lookup specifically so that seam never has to be understood by the person buying the shoes. And a traveller picking up a replacement pair abroad mid-trip, with no way to try shoes on quietly at leisure, measures a foot against a hotel-room ruler and gets a reliable size on the spot rather than guessing and hoping. Foot length itself, of course, is just a length — the Length Converter covers the cm-to-inches side of that measurement directly. And a gift-buyer working entirely from a size someone mentioned once in passing — "I'm a UK 6" — needs the US and EU equivalents before browsing a specific retailer's catalogue, since most sites default to whichever system their home market uses regardless of where the shopper is actually located.
Getting a Measurement You Can Actually Trust
A foot measured barefoot in the morning and the same foot measured in a sock at 7pm can differ by more than a full size boundary, so a few habits make the difference between a conversion that's accurate and one that just looks precise. Measure both feet, not just one — it's genuinely common for one foot to run slightly longer, and the larger of the two should decide the size. Measure standing with full weight on the foot rather than sitting, since a foot spreads noticeably under load. If the shoe is meant to be worn with thick socks or an orthotic insert, measure with those already on, because a bare-foot reading will run a touch small for that specific use case. And for kids specifically, treat any measurement as temporary: a foot that grows even half a centimetre in a few months is enough to justify checking again before the next pair of shoes rather than trusting last season's size.
Built Around the One Number That Doesn't Lie
Rather than trying to convert a size label you already have — which only compounds whatever inaccuracy was already baked into that original label — this tool starts from foot length and derives every system from the same real, cross-checked size charts. Jump-to-size buttons let you start from a known US or kids size instead if that's more convenient, setting the equivalent foot length behind the scenes so everything else still stays in sync. When a measurement lands between two half sizes, a note appears recommending you size up, standard advice from footwear fitters for exactly that situation. Underneath the main result, a full clickable size chart lists every size in the selected category with the closest match to your current measurement highlighted, and a short measuring guide walks through getting an accurate foot length at home with nothing more than a wall and a sheet of paper — no printer-calibrated ruler graphic to line up against a screen, no app download, just a measurement anyone can take in under a minute and reuse for every shoe purchase afterward.
Why the Label Never Has the Final Word
Even a perfectly accurate size conversion has a limit this tool can't engineer around: shoe sizing was never standardised the way physical units like length or weight eventually were, so a size 9 from one brand and a size 9 from another can measure differently depending on the last — the foot-shaped mould each shoe was actually built around. Treat every conversion here, and from any similar tool, as a strong starting estimate rather than a guarantee, and check a specific brand's own chart directly whenever it's available, especially before a first order from an unfamiliar label. Nothing typed into this tool is sent anywhere: the calculation runs as plain JavaScript inside the browser tab, with no server call and nothing logged, which matters whether you're sizing one pair or checking sizes for an entire family at once, and the tool keeps working identically with no internet connection at all once the page has loaded. For anything with real money riding on getting it exactly right — a non-refundable overseas order, a bulk purchase for a sports team — measuring directly against the specific brand's own published chart remains the safest final check.