UK Shoe Size Calculator & Conversion Chart 2025

Shoe sizes vary significantly between countries and even between brands within the same country. Understanding the differences between UK, US, and European sizing systems is essential for buying shoes online, shopping abroad, or converting sizes when reading international reviews.

This guide provides comprehensive conversion charts for men's, women's, and children's shoes, explains how to measure your feet accurately, and helps you understand width fittings—particularly important in the UK where E and EE fittings are commonly available.

Men's Shoe Size Conversion

Women's Shoe Size Conversion

How to Measure Your Feet

1. Stand on paper against a wall
2. Mark the longest toe and heel
3. Measure the distance in cm
4. Measure both feet (they may differ)
5. Use the larger measurement
6. Measure in the afternoon (feet swell)

Width Fittings

UK Shoe Sizing History

UK shoe sizes are based on the barleycorn system, where 3 barleycorns equal 1 inch (2.54 cm). Each full size increment represents 1/3 inch (8.47mm). This traditional measurement system dates back centuries and differs from the metric-based EU system.

Brand Sizing Variations

Some brands are known to run differently:

When Shoe Size Changes

Your shoe size can change throughout life:

• Pregnancy: Feet often increase half to full size permanently
• Weight changes: Significant gain/loss affects foot width
• Age: Feet tend to lengthen and widen with age
• Time of day: Feet swell by evening—buy shoes in afternoon
• Activity: Athletes may need larger sizes for swelling

Children's Sizes

UK vs US vs EU Shoe Size Conversion

Converting shoe sizes between different systems is essential when buying footwear from international retailers. The UK, US, and EU systems all use different scales, and the conversions differ between men's and women's shoes.

Women's Shoe Size Conversion

• UK 3 = US 5 = EU 36
• UK 4 = US 6 = EU 37
• UK 5 = US 7 = EU 38
• UK 6 = US 8 = EU 39
• UK 7 = US 9 = EU 40-41
• UK 8 = US 10 = EU 42
• UK 9 = US 11 = EU 43

Men's Shoe Size Conversion

• UK 6 = US 7 = EU 39-40
• UK 7 = US 8 = EU 41
• UK 8 = US 9 = EU 42
• UK 9 = US 10 = EU 43
• UK 10 = US 11 = EU 44-45
• UK 11 = US 12 = EU 46
• UK 12 = US 13 = EU 47

The key difference between UK and US sizing is that US sizes are typically 1 size larger for women (UK 5 = US 7) and 0.5 to 1 size larger for men (UK 9 = US 10). EU sizes use a completely different numbering system based on the Paris point, where each size represents approximately 6.67mm of foot length.

Children's Shoe Sizes in the UK

Children's shoe sizing in the UK follows a different scale from adult sizes. Children's feet grow rapidly, and it is important to measure regularly to ensure proper fit.

• Baby/Infant (0-2 years): UK sizes 0-4. Start measuring from birth. First shoes are typically needed when a child begins walking confidently, usually between 12 and 18 months.
• Toddler (2-4 years): UK sizes 4-9. Feet should be measured every 6-8 weeks as they can grow up to 2 sizes per year at this age.
• Junior (4-8 years): UK sizes 9-13. Growth rate slows slightly but regular measuring every 2-3 months is still recommended.
• Senior (8-12 years): UK sizes 1-5.5 (moving into adult sizing). By around age 12-13, many children transition to adult sizes.

The Clarks foot gauge, widely available in UK shoe shops, is the most commonly used tool for measuring children's feet. It measures both length and width simultaneously. The NHS recommends having children's feet measured by a trained shoe fitter, as poorly fitting shoes can cause long-term foot problems.

Width Fittings Explained

Shoe width is just as important as length for a comfortable fit, yet many people only consider length when buying shoes. UK shoe width fittings use a letter system:

• C or D fitting: Narrow width. Less commonly stocked but available from specialist retailers.
• E fitting: Standard width for women's shoes. This is the default width at most UK shoe shops.
• F fitting: Standard width for men's shoes. Most men's shoes sold in the UK are F fitting unless otherwise stated.
• G fitting: Wide width. Suitable for those who find standard width shoes too tight. Available from most major UK shoe retailers including Clarks, M&S, and Next.
• H fitting: Extra wide width. Available from specialists and brands such as DB Shoes, Cosyfeet, and Hotter.
• EEE/EEEE fitting: Some brands, particularly those aimed at comfort or specialist medical needs, use a different width system with multiple E letters indicating increasing width.

If you frequently experience discomfort, blisters, or bunions, you may be wearing the wrong width. Having both the length and width of your feet measured ensures the best possible fit.

How to Measure Your Feet at Home

You can accurately measure your shoe size at home using the following method:

• Step 1: Place a piece of A4 paper on a hard, flat floor surface. Stand on the paper with your full weight on the foot, wearing the type of socks you would normally wear with shoes.
• Step 2: Using a pen held vertically, mark the tip of your longest toe and the back of your heel on the paper.
• Step 3: Measure the distance between the two marks in centimetres or millimetres using a ruler.
• Step 4: Repeat for the other foot. It is normal for one foot to be slightly larger than the other; always buy shoes to fit the larger foot.
• Step 5: Measure at the end of the day when your feet are at their largest, as feet swell slightly during the day.

For width measurement, mark the widest part of your foot on each side while standing with full weight, then measure the distance between those marks. Compare both your length and width measurements to a shoe size chart to find your correct UK size and fitting.

Frequently Asked Questions

Why are my shoe sizes different between brands?

Unlike clothing, shoe sizes in the UK are based on a standardised system (the barleycorn system, where each size is one-third of an inch). However, different brands use different lasts (the moulds around which shoes are built), which means the internal space of a shoe can vary significantly even at the same nominal size. Italian and European brands tend to run narrower, while brands like Clarks and Skechers tend to offer a more generous fit.

Should I buy shoes in the morning or evening?

Always try on shoes in the afternoon or evening. Feet swell by approximately 5-8% during the day due to walking and gravity. Buying shoes in the morning when your feet are at their smallest can result in footwear that feels too tight later in the day. This advice applies to both in-store purchases and when measuring at home for online orders.

How much room should be in front of my toes?

There should be approximately 10-15mm (about a thumb's width) between the end of your longest toe and the front of the shoe. This allows for natural foot movement during walking and prevents issues such as ingrown toenails and hammer toes. For running shoes, allow slightly more room of 15-20mm to account for foot expansion during exercise.

Do shoe sizes change with age?

Yes. Adult feet can change size over time due to factors such as weight changes, pregnancy, ageing, and medical conditions. The arches of the feet tend to flatten with age, making feet longer and wider. It is advisable to have your feet measured every one to two years, or whenever you notice changes in how your shoes fit.

UK Shoe Sizing: Standards and Industry Facts

The UK shoe sizing system is one of the oldest standardised measurement systems still in use, dating back to the reign of King Edward II in the 14th century. The system is based on barleycorns, an old English unit of measurement equal to one-third of an inch (approximately 8.46 millimetres). Each full UK shoe size represents a difference of one barleycorn (8.46mm) in foot length, with half sizes representing 4.23mm increments. A UK size 0 for children starts at 4 inches (100mm) of foot length, and the scale runs consecutively through to adult sizes.

The UK footwear industry is worth approximately 12 billion pounds in retail sales annually, with British consumers buying an average of 5 pairs of shoes per person per year. Online shoe purchases now account for over 35 percent of the market, making accurate size knowledge more important than ever. ASOS, Schuh, and Office report that shoes are among the most frequently returned items due to sizing issues, with return rates of 25 to 40 percent adding significant cost to both retailers and consumers.

Unlike clothing sizes, UK shoe sizes do have a technical standard (BS 4953), although adherence varies between manufacturers. Width fittings are an important but often overlooked aspect of UK shoe sizing. Standard UK widths are designated by letters: D (narrow), E (standard), F (standard-wide), G (wide), H (extra-wide), and EEE or EEEE (very wide). However, most high street retailers only stock E or F fittings, meaning that consumers with narrow or wide feet often need to visit specialist retailers such as Clarks, Hotter, or DB Shoes for a proper fit.

Children's feet grow rapidly, and the Society of Shoe Fitters recommends measuring children's feet every 6 to 8 weeks for under-5s and every 3 to 4 months for school-age children. A properly fitting shoe should have approximately 12 to 15 millimetres of growing room beyond the longest toe. Clarks and Start-rite both offer in-store foot measuring services across their UK outlets, with Clarks also providing a digital measuring tool through their app.

Shoe Fitting Tips for UK Consumers

• Measure both feet: Most people have one foot slightly larger than the other. When buying shoes, always fit to the larger foot. UK shoe shops with trained fitters will measure both feet using a Brannock device or similar gauge.
• Shop in the afternoon: Feet swell throughout the day due to gravity and activity. The British Footwear Association recommends trying on shoes in the late afternoon or evening when your feet are at their largest to ensure a comfortable fit that accounts for natural swelling.
• Consider width as well as length: Many UK shoe problems are caused by wearing the correct length but wrong width. If you experience pinching, blisters, or bunions, ask for a width fitting. Specialist UK retailers like Clarks, Hotter, and Padders offer multiple width fittings across their ranges.
• Measure children's feet regularly: Children's feet can grow by 2 to 3 full shoe sizes per year. Having feet measured professionally every 6 to 8 weeks for toddlers and every 3 months for older children helps prevent foot problems caused by ill-fitting shoes.

Shoe Size Questions

Dr. Sarah Chen, PhD

Research Scientist, Public Health

Sarah holds a PhD in Public Health from the University of Edinburgh and has published research on UK health metrics and obesity trends. She translates complex medical data into practical, accessible guidance for everyday readers.