Size 4 in EU: Complete UK Shoes & Clothes Guide

Anyone who’s tried to order shoes from a European retailer while working with UK sizing already knows the confusion — a size 4 in the UK isn’t always a straightforward swap in EU sizing, and the gap between 36 and 37 trips up plenty of shoppers. This guide cuts through the charts used by Irish retailers to give you exact conversions for shoes and clothing, backed by measurement data rather than guesswork.

UK Women’s Size 4 Foot Length: 229mm · Recommended Shoe Internal Length for UK 4: 236-248mm · Common UK 4 to EU Conversion: EU 36 or 37 depending on brand

Is a UK Size 4 an EU 36 or EU37?

The short answer from retailer charts is that UK women’s size 4 most commonly converts to EU 37, though the exact number depends on the brand and the type of shoe. Irish sportswear retailer O’Neills lists women’s UK/Ireland size 4 as equivalent to EU 37, US 6, and Australian size 6, with a foot length of 229mm. This gives you a concrete anchor point to work from.

Women’s shoes

For women’s shoes, the conversion gets slightly more complex because different retailers apply different rounding rules. O’Neills places UK size 4 at EU 37, while some other European retailers show EU 36 for the same UK size, particularly for narrower fits or dress shoes where brands build in less interior space. The reason for the one-size gap comes down to the EU sizing formula: to convert UK to EU, you add 33 to the UK size. Working through the math, UK 4 plus 33 equals EU 37 — which is exactly what O’Neills shows.

Brand variations

Beck Shoes notes that each sizing system has unique measurements, meaning a size 10 in the US is not the same as a size 10 in the UK or EU. Luxury brands like Prada add further complexity — Nordstrom’s official size guide shows that Prada men’s US size 6 corresponds to EU 39 and UK size 5, demonstrating that brand-specific sizing can deviate significantly from standard conversion formulas.

What size is 4 in Ireland?

In Ireland, shoe sizing follows the UK system directly — there is no separate Irish shoe size scale. This means when an Irish retailer lists a shoe as UK size 4, that is the size you should order. The O’Neills sizing chart confirms that women’s Ireland/UK size 4 converts to EU 37, US 6, and measures 229mm in foot length. Irish shoppers benefit from this direct alignment because they can use UK sizing charts without any conversion adjustment.

Shoe sizes

Guineys, a long-established Irish retailer, provides sizing guidance that confirms the UK-to-Ireland alignment. Their size guide focuses on the differences between Irish and UK sizing — which are negligible for most purposes — and helps shoppers understand how to measure their feet accurately for the best fit. For UK size 4 specifically, an Irish shopper would look for EU 37 when ordering from European retailers, or EU 36 for brands that run slightly small.

Guineys guide

The practical advice from Irish retailers like Guineys is to measure your foot length in millimetres and match it to the internal length of the shoe rather than relying on the numerical size alone. For UK size 4 with a 229mm foot, retailers typically recommend shoes with an internal length of 236-248mm to allow for toe movement and socks. This gives you a more reliable fit than the number on the box.

The pattern: Irish shoppers should treat UK size as their home base, then add 33 for the EU equivalent.

Is size 4 a 36 or 37?

For women’s shoes specifically, UK size 4 most often lands at EU 37. This holds true for athletic footwear, casual shoes, and most boots. However, dress shoes and some European brands may list the same UK size as EU 36, particularly when they design for a narrower fit or build in less interior cushioning. The variation means that the answer depends partly on the shoe type and the specific brand.

Shoe conversions

Laughing Hens, which publishes conversion charts for multiple regions, confirms that EU size 4 in children’s shoes converts to UK size 6 and US size 7, and that EU size 4 in men’s shoes converts to UK size 5.5 and US size 6.5. These conversions show that the formula shifts between categories, which is why women’s UK size 4 does not follow the same path as EU size 4 in other genders.

Clothing context

In clothing, UK size 4 typically refers to a small or XS, though sizing varies significantly between brands. ASOS publishes brand-specific women’s clothing size charts where UK size 4 may map differently than in footwear. The key takeaway from retailers like ASOS is that clothing size 4 and shoe size 4 do not share a conversion — they are separate scales that happen to use the same number.

What this means: the number 4 carries different measurements depending on whether you’re shopping shoes or clothes.

What is size 4 in EU clothes?

For women’s clothing, UK size 4 typically corresponds to a XS or small in EU sizing, though exact conversions vary by retailer. ASOS uses brand-specific size charts where UK size 4 may translate to EU 34, 36, or another size depending on the brand’s fit philosophy. Unlike shoe sizing, clothing size conversions are less standardized and depend heavily on the specific retailer and garment type.

Women’s sizing

Kiwi Sizing provides reference information indicating that size 4 is typically classified as small in women’s clothing, but this classification is not universal. Some European brands consider UK size 4 equivalent to EU 34, while others place it at EU 36 or EU 38 depending on the cut and intended fit. The variation means that for clothing purchases from EU retailers, checking the retailer’s specific size chart is essential rather than relying on a standard conversion number.

ASOS charts

ASOS recommends using their brand-specific size guides when shopping, as different brands fit differently even when using the same UK size notation. For UK size 4 specifically, ASOS shows that EU equivalent sizes vary, with some brands recommending EU 36 and others suggesting EU 34 or EU 38 depending on the garment’s cut. This brand-by-brand variation is why ASOS explicitly advises shoppers to check each product’s individual size guide rather than applying a single conversion factor.

The catch: clothing brands treat the same numerical size differently, so a UK 4 from one retailer may fit like EU 34 while another brands it as EU 38.

Is a size 4 a small?

In women’s clothing, a UK size 4 is generally considered equivalent to a small or XS, though the exact label depends on the brand. Most UK and Irish retailers classify size 4 as small for women, with some using XS for more fitted styles. For men’s clothing, size 4 is less common as a label and typically refers to specific measurements rather than a standard size designation.

Clothing

Kiwi Sizing provides a reference indicating that size 4 corresponds to a small number in women’s sizing, though they note that size classifications vary by region and brand. The pattern across retailers is consistent: for women, size 4 is at the smaller end of the standard range, typically fitting busts of 32-34 inches depending on the brand’s fit preference.

Shoes

In footwear, the concept of “small” does not apply to numerical sizing the same way. UK size 4 in women’s shoes is considered a smaller size, but the EU equivalent of 37 puts it in the middle of the standard EU women’s range. This disconnect between clothing and shoe sizing means that a shopper who wears a UK size 4 small in clothing may still need EU 37 in shoes — the scales simply do not align the same way.

The implication: a UK 4 in shoes and a UK 4 in clothing cover different body measurements — shop each category separately.

Size 4 EU Conversion Table: Women’s Footwear

Three retailers, three slightly different recommendations — here is how the conversions stack up for women’s UK size 4 across the Irish and UK market.

What this means: even the retailers disagree by half a size, which is why relying on a single chart risks an ill fit.

UK to EU Shoe Size Formula Reference

Five key facts about how UK and EU shoe sizing relate, drawn from sizing guides used by retailers and brands across markets.

The pattern: the simple add-33 formula works for standard retailers but luxury brands routinely deviate from it.

Clarity on What We Know vs What Remains Uncertain

What the Experts Say

Each sizing system (US, UK, EU) has its unique measurements and standards, meaning that a size 10 in the US is not the same as a size 10 in the UK or EU.

— Beck Shoes (footwear retailer and sizing guide publisher)

Relying on the number alone without consulting a conversion chart can result in purchasing shoes that are too small or too large.

— Beck Shoes (footwear retailer and sizing guide publisher)

Summary

For Irish and UK shoppers looking for size 4 in EU sizing, the practical path forward is straightforward: start with EU 37 for women’s footwear as your default, then verify against the specific retailer’s chart before purchasing. The 229mm foot length measurement gives you a concrete reference point when in doubt. Clothing conversions require a separate check against each brand’s specific size chart, since no universal UK 4 to EU clothing conversion exists. For anyone navigating cross-border shopping, the measurement in millimetres beats the number on the box every time.

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Much like size 4 mapping to EU 37 via O’Neills and Pavers, size 5 UK in EU shoes aligns with EU 38 across ASOS and similar retailers.

Frequently asked questions