Shoe Size Converter (UK, US, EU, CM)

Shoe Size Conversion Guide

Why Shoe Sizes Differ?

Shoe sizing systems vary by country and there's no single global standard, which makes buying shoes from abroad or online confusing. The main systems are: UK sizing — based on the length of the last (the foot-shaped mould), using barleycorns (1/3 inch) as the unit. US sizing — similar to UK but offset by about half a size for adults (US sizes run higher than UK for the same foot), and men's and women's US sizes differ from each other. EU sizing (Continental/Paris point) — used across Europe, based on 2/3 cm increments, so EU numbers are larger (a UK 8 is roughly EU 42). Japanese/CM sizing — refreshingly logical, simply the foot length in centimetres. Mondopoint (the cm-based system) is used for ski boots and by the military. Because the systems use different units and starting points, conversions aren't always exact, and they vary slightly between manufacturers. The most reliable basis for conversion is actual foot length in centimetres, which is why measuring your foot is the surest way to get the right size — especially when ordering from a different country's sizing. For clothing sizes across all brands and countries, <a href="https://247sizing.com" rel="noopener">247 Sizing</a> has comprehensive size conversion charts for tops, bottoms, dresses, and more.

What's the key thing to understand about Measuring Your Feet?

The most accurate way to find your size is to measure your foot length, then convert. How to measure: stand on a piece of paper (standing puts your foot under load, giving a true size — feet spread when bearing weight). Mark the longest point (usually the tip of the big toe, but sometimes the second toe) and the back of the heel. Measure the distance in centimetres. Do both feet — they're often slightly different, and you should size to the larger foot. Measure at the end of the day, when feet are at their largest (they swell during the day). Add a little room: most fitting guides suggest leaving roughly 1-1.5cm between your longest toe and the end of the shoe for comfort and movement — so add this to your measured length, or use a chart that already builds it in. Width matters too: length isn't everything. Some people need wider or narrower fittings (UK shoes often come in width fittings like D, E, EE). A shoe of the right length can still fit poorly if the width is wrong. For children, measure regularly (their feet grow fast) and leave growing room — but not too much, as overly large shoes affect gait and safety.

What do I need to know about Getting Online Orders Right?

Buying shoes online removes the chance to try them on, so a few precautions reduce the frustration of wrong sizes. Use foot length, not your 'usual size': measure your foot in cm and use the retailer's specific size chart (many list foot length in cm against their sizes). Brands and even styles within a brand vary, so your 'usual UK 8' may not be their UK 8. Check the brand's own chart: don't assume a generic conversion — reputable retailers publish size guides, sometimes with model-specific advice ('runs small', 'fits large'). Read reviews for sizing notes: other buyers frequently mention whether a shoe runs small or large, which is invaluable. Consider the country of origin: an American brand may use US sizing; a European brand EU sizing — convert carefully. Account for the type of shoe: trainers, boots, and formal shoes fit differently; some need room for thick socks (winter boots) or a snug fit (running shoes). Returns policy: check it before ordering, and if unsure between two sizes, order both and return one (where free returns allow) rather than guessing. This converter helps translate between systems, but pairing it with your measured foot length and the retailer's chart gives the best results.

What do I need to know about Fit Beyond the Number?

The size number is a starting point; genuine fit involves more. Width and volume: feet vary in width and instep height. A shoe can be the right length but pinch (too narrow) or slip (too wide). Look for width fittings if standard widths don't suit you. Shape: shoes have different toe-box shapes (pointed, rounded, square) — match the shape to your foot, especially if you have wider toes or conditions like bunions. Time of day and socks: try shoes (or judge fit) at the end of the day with the socks you'll wear them with. Both feet: fit to your larger foot; never squeeze the bigger foot into a size that fits the smaller. Break-in vs pain: leather may ease slightly, but shoes shouldn't be painful when new — 'breaking in' won't fix fundamentally wrong sizing. Children's feet: check fit regularly as they grow (every few months for young children); ill-fitting children's shoes can affect foot development. Signs of poor fit: blisters, numbness, toes touching the end, heel slipping, or pressure points all indicate the wrong size or shape. The right shoe should feel comfortable immediately, with room to wiggle toes and no pinching. This converter and the measuring guide help you start from the right number; trust how the shoe actually feels over the label.

Worked Example: Converting a UK Size 8 to US and EU

Shoe size systems do not share a common origin point, so conversions use approximate offset formulas rather than a single clean ratio. For a typical men's shoe, a common approximation is: US size ≈ UK size + 1, and EU size ≈ UK size + 33 (varies slightly by brand and last/shape). For a UK size 8: US size ≈ 8 + 1 = 9, and EU size ≈ 8 + 33 = 41. For women's sizing the US offset is usually larger — commonly US (women's) ≈ UK + 2 — so the same UK size 8 would convert to roughly US women's 10, which is why checking whether a size chart is labelled men's, women's, or unisex matters as much as the number itself. These offsets are approximations rather than exact standards; the only fully reliable method is checking the specific brand's own size chart or, better, matching a measured foot length in centimetres against that brand's chart.

Approximate Size Conversion Reference (Men's, Typical)

Treat this table as a starting estimate rather than a guarantee: 'true size' running shoes, wide-fit lasts, and brands that size generously or small can all shift the real-world fit by half a size or more either way.

Kids' Shoe Sizes Use a Different Scale Entirely

Children's shoe sizing in the UK and US does not simply continue the adult scale — it typically restarts its own numbering (often starting near size 0-1 for toddlers) before transitioning into adult sizes around UK size 13-14 / US size 1-2, depending on the brand's chart. Because growing feet change quickly, many retailers recommend measuring a child's foot length every few months rather than relying on the last known size, and leaving a small amount of growing room (commonly around 1 cm) beyond the measured foot length when buying shoes that need to last.

The Best Time of Day to Measure Your Feet

Feet swell slightly over the course of a day due to gravity and normal fluid movement, typically becoming marginally larger by evening than first thing in the morning. For the most reliable fit, measure feet in the afternoon or evening rather than right after waking up, and always measure both feet separately, since most people have one foot slightly larger than the other — sizing to the larger foot avoids a persistently uncomfortable fit in the smaller shoe of a pair.

Half Sizes and Width Fittings Across Systems

Length isn't the only dimension that varies by country — width fittings are labelled completely differently between US/UK and the rest of the world, and half sizes don't always exist in every system.

This is why a shoe that's the 'right' converted length in a European size can still feel narrow or loose — EU sizing conventionally ignores width altogether, so two people with the same foot length but different foot width get no guidance from the number alone, unlike the US/UK system's explicit width letters.