UK size 9 in EU – Complete Shoe Conversion Guide for Men and Women

Shopping for shoes across different sizing systems can be confusing, especially when converting a UK size 9 to its European equivalent. The answer is not always straightforward because it depends on gender, brand, and even the specific shoe model. For men, a UK 9 typically corresponds to EU 43, while for women, the same UK size usually falls between EU 40 and EU 41. This guide breaks down the conversion with verified data from official size charts and retailers, covering standard conversions, brand-specific nuances for Nike, and the reasoning behind the discrepancies.

Understanding the difference between UK and EU sizing is essential for avoiding returns and ensuring a comfortable fit. UK sizes are gender-specific, meaning a men’s 9 and a women’s 9 refer to different foot lengths. EU sizing, on the other hand, is unisex — the same number applies to both men and women regardless of gender. This fundamental difference is the main reason why a simple one-to-one conversion does not exist for all categories.

The most common question asked by shoppers is straightforward: what is a UK size 9 in EU? The accurate answer requires separating men’s and women’s conversions and then accounting for brand-specific charts, particularly for athletic footwear like Nike. This article provides a complete, fact-based breakdown using official sources and retailer guides.

What is a UK Size 9 in EU Shoe Sizes?

The direct conversion for a UK size 9 depends primarily on whether you are looking at men’s or women’s footwear. Standard conversion tables from major retailers provide clear reference points, but brand variations exist.

Men’s Standard

UK 9 = EU 43 (most brands)

Women’s Standard

UK 9 = EU 40–41 (varies by brand)

Nike (Men)

UK 9 = EU 43 (consistent across most styles)

Nike (Women)

UK 9 = EU 43 (per Nike’s women’s chart; US label differs)

Key Insights at a Glance

Most common conversion: UK 9 men = EU 43; UK 9 women = EU 40–41.
EU sizing is unisex; UK sizing is gender-specific — this often leads women to order the wrong EU size when using men’s conversion charts.
Brands such as Nike and Adidas typically follow the standard conversion but may show half-size variations in specific models.
Shoe width is not captured by length-based conversion — always check width options separately.
For women’s UK 9, the conversion can range from EU 40 to EU 41 depending on the brand and style.
Nike’s own women’s chart places UK 9 at EU 43, which differs from general women’s standards.
Half sizes (e.g., UK 9.5) are not universally available in EU sizing.

UK Size 9 EU Conversion Table

Category	UK 9	EU Equivalent	Notes
Men’s (Standard)	9	43	Applies to most dress, casual, and athletic shoes
Women’s (Standard)	9	40–41	Commonly EU 40, but some brands use 41
Men’s Nike	9	43	Consistent across most Nike styles per official chart
Women’s Nike	9	43	Per Nike’s women’s footwear size chart (US women’s 11 = UK 9 = EU 43)
Half size (men)	9.5	43.5	Only if brand offers half sizes in EU
Half size (women)	9.5	40.5–41.5	Less common in EU women’s sizing

What is UK Size 9 in EU for Nike?

Nike is one of the most searched brands for shoe size conversion, and its sizing behaviour differs from generic charts. According to Nike’s official UK size chart for men’s footwear, a UK size 9 corresponds to EU 43. This is consistent with the standard men’s conversion used by major retailers such as Foot Locker and Famous Footwear.

Nike Men’s UK 9: Confirmed EU 43

Nike’s own size chart for men lists UK 9 directly alongside EU 43. Third-party guides, including those from Nordstrom, confirm this mapping. The conversion remains consistent across most Nike men’s footwear categories, from lifestyle sneakers to performance running shoes.

Nike Women’s UK 9: Also EU 43 (Different US Label)

According to Nike’s official women’s footwear size chart, a UK 9 converts to EU 43, with a US women’s label of 11. This means that for Nike, both men’s and women’s UK 9 map to the same EU 43, but the US gender labels differ — a UK 9 in men’s is US 9.5, while in women’s it is US 11. The EU number remains the same because EU sizing is based on foot length and is unisex.

Brand-Specific Variation

Nike cautions that sizing can vary by model and fit within its own range. The company recommends using its official size charts and measuring foot length in centimetres for the most accurate fit. Third-party reviewers at Sole Review note that certain Nike models, particularly running shoes, may run a half-size small or large.

How Do UK Shoe Sizes Compare to EU Sizes?

The two systems are built on different measurement units, which is why conversion is not a simple mathematical formula. UK sizing is based on barleycorns — one barleycorn equals one-third of an inch — and sizes increase by one-sixth of an inch per half size. EU sizing uses Paris points, where one point equals two-thirds of a centimetre, and sizes increase by two-thirds of a centimetre per full size.

A Rough Formula, Not a Rule

A common approximation for men is EU size = UK size + 33. For women, the formula is roughly EU = UK + 31 or 32. However, these formulas are not precise across the full size range. Because the two systems scale at different rates, a conversion that works at UK 9 may not hold at UK 14. A dedicated conversion table, such as those provided by the ISO 9407:2019 standard, is more reliable than any single formula.

Why UK Sizes Are Gender-Specific

In the UK system, men’s and women’s sizes are on separate scales. A women’s UK 9 is smaller than a men’s UK 9 in terms of actual foot length. EU sizing, by contrast, is unisex — a EU 43 is the same length whether it is sold as men’s or women’s. This difference is the primary source of confusion when converting UK women’s sizes to EU.

Quick Check for Women

If you are a woman who normally wears UK 9 and you are buying a unisex or men’s shoe, your EU size will be 43. If you are buying a women’s-specific shoe from a non-Nike brand, your EU size will likely be 40 or 41. Always verify with the brand’s chart.

What Are the EU Sizes for UK Sizes Close to 9?

Shoppers often compare adjacent sizes when a half size is unavailable or when a brand runs large or small. The table below provides standard conversions for UK sizes 7 through 10 for both men and women.

UK 8 in EU

For men, UK 8 converts to EU 42. For women, UK 8 typically converts to EU 39. These values follow the same standard pattern as the UK 9 conversion.

UK 10 in EU

UK 10 men converts to EU 44. UK 10 women converts to EU 41. These conversions are consistent across most general size charts, including those from Foot Locker and Famous Footwear.

Half Sizes: UK 8.5 and UK 9.5

Half sizes exist in both UK and EU systems, but not all EU brands carry half sizes. UK 8.5 men typically converts to EU 42.5, and UK 9.5 men to EU 43.5 — provided the brand offers half sizes. For women, UK 8.5 converts to approximately EU 39.5, and UK 9.5 to approximately EU 40.5 or 41.5, again depending on brand availability.

How Did UK and EU Shoe Size Systems Develop?

The UK system dates back to the 14th century, when King Edward II standardised the barleycorn as a unit of measurement. Three barleycorns placed end to end equalled one inch, and shoe sizes were based on increments of one barleycorn (⅓ inch). This system was formalised in the 19th century and remains the basis for UK sizing today.

The EU system originated in France during the 18th century using the Paris point, which measures ⅔ of a centimetre. Unlike the UK system, EU sizing was designed to be unisex from the outset, measuring foot length without reference to gender. The two systems developed independently and were never designed to align, which explains why conversion is approximate rather than exact.

Efforts to harmonise sizing internationally have been made through standards such as ISO 9407:2019, which recommends a Mondopoint system based on foot length and width in millimetres. However, the UK and EU systems remain dominant in their respective markets.

What Is Certain and Uncertain When Converting UK 9 to EU?

Some aspects of the conversion are well established, while others require additional verification. The table below separates what is known with high confidence from what remains variable.

Established Information	Information That Remains Unclear
UK 9 men = EU 43 for the vast majority of footwear brands.	Women’s UK 9 conversion can range from EU 40 to EU 43 depending on brand.
Nike men’s UK 9 = EU 43 per official Nike chart.	Nike women’s UK 9 = EU 43 on Nike’s chart, but many general guides list it as EU 40–41.
EU sizing is unisex; UK sizing is gender-specific.	No single official standard enforces exact matching between UK and EU scales.
Foot Locker, Famous Footwear, and Nordstrom charts agree on UK 9 men = EU 43.	Half-size conversions (e.g., UK 9.5 to EU) are not consistently offered across all brands.

Recommendation for Reliable Fit

Always consult the brand’s own size chart before purchasing. Measure your foot length in centimetres and compare it to the brand’s cm-to-size guide whenever possible. The EU system is based on foot length, so cm measurement is the most reliable cross-reference.

Why Do UK and EU Sizes Not Always Match?

The UK system originates from barleycorn units (⅓ inch steps), while the EU system uses Paris points (⅔ cm). These are not simple multiples of each other, so conversion tables are inherently approximate. Additionally, women’s UK sizes are smaller than men’s for the same EU number, because EU sizes are unisex but UK women’s sizing is offset from men’s by approximately two sizes.

Many online guides oversimplify the conversion by offering a single number for all categories, which leads to returns and confusion. For example, a woman wearing UK 9 who uses a men’s conversion chart will order EU 43, but unless she is buying Nike or another brand where women’s UK 9 maps to EU 43, the shoe will likely be too long. The NHS foot health guide recommends measuring both feet and fitting to the larger one, regardless of size label.

What Do Official Sources Say About UK 9 to EU Conversion?

Retailers and brands that provide size charts are the most reliable sources for conversion data. Below are key quotes from official and expert sources.

A UK size 9 for men can be equivalent to an EU size 43.

— Foot Locker UK guide (2025)

EU sizes do not translate directly to UK sizes. Typically they jump around 5/6 of a UK size, for every EU size on the scale.

— Begg Shoes blog (Dec 2025)

UK 9 corresponds to EU 43 (as per Nike’s official chart).

— Nike UK men’s footwear size chart

These sources consistently confirm that UK 9 men maps to EU 43 for standard and Nike footwear. For women’s Nike, Nike’s own chart also shows UK 9 = EU 43, though general women’s charts from other retailers often list EU 40 or 41.

What Should You Remember When Converting UK Size 9 to EU?

For men’s shoes, UK 9 is reliably EU 43 across most brands, including Nike. For women’s shoes, the conversion is less uniform — standard women’s sizing places UK 9 at EU 40–41, while Nike’s women’s chart places it at EU 43. The key takeaway is to check the brand-specific size chart, measure your foot in centimetres, and treat any formula or table as a starting point rather than a guarantee. For related guidance on Nike product sizing, see the Nike Dri-FIT T-Shirt: Complete Guide for Men, Women, Kids.

Frequently Asked Questions About UK 9 to EU Conversion

What is UK size 8 in EU?

UK 8 men = EU 42; UK 8 women = EU 39 (standard conversion).

What is UK size 10 in EU?

UK 10 men = EU 44; UK 10 women = EU 41 (standard conversion).

Do EU shoe sizes differ for men and women?

No — EU sizes are unisex. A EU 43 is the same length for men and women. UK sizes are gender-specific, which causes the confusion.

Is UK size 9 the same as EU 43 for all brands?

Mostly yes for men’s, but some brands may run slightly larger or smaller. Always check the brand’s own size chart.

How to convert UK shoe size to EU?

A common formula for men: EU ≈ UK + 33. For women: EU ≈ UK + 31 or 32. These are rough estimates — use a size chart for accurate conversion.

What is UK size 9 in EU for Adidas?

Adidas men’s UK 9 is typically EU 43. Adidas women’s UK 9 is typically EU 40–41. Check Adidas’s official chart for model-specific details.

Does UK 9 in EU apply to children’s shoes?

Children’s UK sizes follow a different scale. UK 9 in children’s is a much smaller size, typically around EU 26–27. This guide covers adult sizes only.

What should I do if my shoes still don’t fit after conversion?

Return the shoes and re-check the brand’s cm-to-size chart. Measure your foot length in cm at the end of the day when feet are slightly swollen for best results.