Why use this calculator
Four countries invented four different ways to measure the same foot, and none of them measures the foot directly. The US and UK scales count barleycorns, a third of an inch each, from different starting points. Europe counts Paris points, two thirds of a centimetre each, and measures the last rather than the foot.
Japan and much of Asia simply state the foot length in centimetres, which is the only honest system of the four. On top of that every manufacturer builds on its own lasts, so two shoes marked the same size can differ by a full size.
This converter gives you the whole picture at once, including the foot length behind the number, so you can compare against any brand's own chart instead of guessing.
How to use it
- Choose the system your known size belongs to first, because the valid range changes with it: a European size is a number in the thirties or forties while a US size is a single-digit or low double-digit figure.
- Then enter the size itself, using half sizes where your shoes use them.
- If you know your foot length, choose the foot length option and enter the measurement in centimetres instead, which is the most reliable route because it skips the manufacturer's interpretation entirely.
- To measure, stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe, and measure the distance in the late afternoon when your feet are at their largest.
- Compare the recommended inside length against any brand chart that publishes one.
What each result means
- US Men's
- The size in the United States men's scale, which is the pivot every other conversion here is calculated through.
- US Women's
- The United States women's equivalent, conventionally one and a half sizes above the men's number for the same foot.
- UK
- The British size, which runs about half a size below the US men's number because the two scales start from different points.
- EU
- The Continental European size in Paris points. Whole numbers are the norm, so round when ordering.
- Foot length (cm)
- The heel-to-toe length of the foot this size is built for, and the only figure that is comparable across every brand.
- Foot length (inches)
- The same measurement in inches, which is the unit the US and UK barleycorn scales are actually derived from.
- JP / Mondopoint (cm)
- The Japanese, Chinese and Korean size, which states foot length directly to the nearest half centimetre.
- Recommended inside length (cm)
- The internal length a shoe should have for this foot, allowing roughly a thumb's width of room in front of the toes.
The formula
Everything is converted through US men's sizing as a common pivot.
US women's size = US men's plus 1.5
UK size = US men's minus 0.5
EU size = US men's plus 33.5
Foot length follows the barleycorn scale, where a men's size 1 corresponds to a foot 7 and 2/3 inches long and every whole size adds one third of an inch: foot length in inches = (US men's size plus 22) divided by 3, then multiplied by 2.54 for centimetres. Mondopoint, used across Japan, China and Korea, is the foot length in centimetres rounded to the nearest half centimetre. Fitting allowance adds about 1 cm in front of the longest toe.
How this number is used in practice
Sizing drift between brands is the reason conversions can only ever be a starting point. Running brands in particular build on narrow, long lasts and many runners buy half a size to a full size above their everyday shoe, because feet swell on a long run and a toe hitting the front of the shoe on every descent is how toenails are lost.
Formal leather shoes often run large because the last is shaped for a slimmer foot, while work boots run wide and short. The foot length row is the one that lets you cut through all of this, because most manufacturers publish a length chart even when their size labels are idiosyncratic.
Width is the dimension the size number ignores completely, and it causes more discomfort than length. The US system has letter widths from AA through EEEE, the UK uses F, G and H fittings, and Continental Europe frequently offers no width choice at all, which is why a European size that matches on length can still pinch.
If a shoe is uncomfortable across the ball of the foot but the length is right, the answer is a wider fitting, not a larger size: going up a size to gain width also adds length, and a foot sliding forward inside a too-long shoe causes its own set of problems.
Two other practical points. Feet are commonly different sizes, so always fit to the larger foot and use the lacing or an insole to take up the slack in the other. And feet change over a lifetime: they lengthen and widen with age, pregnancy and weight change, so a size you have bought for a decade may no longer be right. Measuring again takes two minutes and is worth doing whenever a familiar size stops feeling familiar.
Worked examples
A US men's size 10
US women's 11.5, UK 9.5, EU 43.5, and a foot length of 27.1 cm.
A European size 42
US men's 8.5, US women's 10.0, UK 8.0, and a foot length of 25.8 cm.
A measured foot length of 24.0 cm
US men's 6.3, US women's 7.8, UK 5.8 and EU 39.8, so a whole EU 40 is the size to try.
A UK size 7
US men's 7.5, US women's 9.0, EU 41.0, and a foot length of 25.0 cm.
When people use it
- Ordering shoes from an overseas retailer that lists only one sizing system
- Converting between men's and women's sizing when buying unisex models
- Turning a measured foot length into a size to try in any country
- Checking a child's or partner's size against a brand chart before buying a gift
- Comparing a new brand's chart against the size you normally wear
Tips
- Measure your foot rather than trusting a remembered size. Foot length in centimetres is the only figure that compares across every brand.
- Measure in the late afternoon or after walking, when feet are at their largest. A morning measurement will give you a shoe that is too tight by evening.
- Fit to your larger foot. Most people have a noticeable difference between the two and fitting to the smaller one guarantees discomfort.
- Allow about a thumb's width, roughly a centimetre, between your longest toe and the end of the shoe.
- If the ball of your foot is pinched but the length is right, you need a wider fitting, not a bigger size.
- Many runners size up by half a size for distance shoes, because feet swell and toes need room on downhill sections.
- Treat every conversion as a starting point and check the manufacturer's own chart, since lasts vary by as much as a full size between brands.
What it assumes, and where it stops being accurate
- Conversions use the standard linear relationships between the systems and cannot capture individual manufacturers' lasts.
- Sizes here are adult sizes. Children's scales restart at different points in every system and are not covered.
- Width is not considered at all, even though it is the most common cause of a poor fit.
- Foot length uses the barleycorn scale, where each whole size is one third of an inch, which is a convention rather than a measured average.
- EU sizes are shown to one decimal place for comparison, but shoes are only manufactured in whole Paris points.
- Half sizes are widely offered in the US and UK and are much less common in the EU system.
Terms used on this page
- Barleycorn
- A third of an inch, the historic step between whole sizes in the UK and US systems.
- Paris point
- Two thirds of a centimetre, the step between whole sizes in the European system.
- Last
- The foot-shaped form a shoe is built around, which determines its true fit far more than its size label.
- Mondopoint
- The ISO system that expresses shoe size as the foot length in millimetres, sometimes with a width.
- Width fitting
- A letter or letter-pair marking how wide a shoe is at a given length, such as D, E or EEEE.
Questions people ask
- Are shoe size conversions exact?
- No, and they cannot be. Each system measures something slightly different, and manufacturers build on their own lasts, so two shoes marked the same size can differ by a full size. Use the conversion as a starting point and confirm against the brand's own chart, ideally one that publishes foot length.
- What is the difference between US men's and women's sizes?
- For the same foot, the US women's number is conventionally one and a half sizes above the men's number, so a men's 9 is a women's 10.5. The lasts also differ in shape, being narrower through the heel and generally lower in volume, which matters as much as the number does.
- How do I measure my foot properly?
- Stand on a sheet of paper with your heel against a wall, weight on both feet, and mark the tip of your longest toe. Measure the heel-to-mark distance in centimetres and repeat for the other foot. Do it in the late afternoon and use the larger measurement.
- What is Mondopoint?
- It is the ISO sizing system that states foot length directly in millimetres, often with a width figure alongside. It is used across Japan, China and Korea, in ski boots and in military footwear, and it is the only system where the number on the box tells you a real dimension of your foot.
- Why do European sizes not have half sizes?
- Because a Paris point is only two thirds of a centimetre, so consecutive whole EU sizes are already closer together than consecutive US or UK sizes, which step by a third of an inch, about 0.85 cm. The finer steps make half sizes largely unnecessary in the European system.
- Should I size up for running shoes?
- Often, yes. Feet swell during exercise and toes slide forward on descents, so many runners take half a size more than their everyday shoe and check that a thumb's width remains in front of the longest toe when standing. Fit late in the day and wear the socks you will run in.
Use this with
Shoe Size Converter answers one part of the question. These pick up where it stops: Length Converter, Unit Price Comparison Calculator, BMI Calculator and Ideal Weight Calculator.
Where these figures come from
This calculation is jurisdiction-neutral arithmetic. No country-specific rules are applied.
- ISO: International Organization for Standardization. Publisher of ISO 9407, the Mondopoint shoe-sizing system based on foot length in millimetres
- NHS: Health A to Z. Public health guidance on foot problems caused by poorly fitted footwear
Shoe Size Converter produces an estimate for general information. It is not financial, tax, medical, legal or engineering advice. read the full disclaimer. Spotted a wrong number? Report it and it gets fixed. The form picks up this calculator and the inputs you used.