Shoe Sizes Around the World: Why Charts Disagree

How the systems are built

• US and UK: each full size step is one barleycorn, a third of an inch (8.47 mm). The two scales start from different points, and men's, women's and children's scales are listed separately.
• EU (Paris point): each size is one Paris point, two thirds of a centimeter (6.67 mm).
• Mondopoint: states the foot length in millimeters, so a mondopoint of 265 fits a foot of about 265 mm. It is used on ski boots and some outdoor and work boots.
• Japan: sizes are normally given as the foot length in centimeters, such as 26.0.
• Children's sizes: US and UK children's scales run up to 13 and then restart at 1, so a child's 13 is smaller than an adult's 1. Always check whether a chart means a child, youth or adult size.

Half sizes exist in the US and UK. A half size is half a barleycorn, about 4.2 mm, which is why a shoe one half size off can feel noticeably different.

Because a US or UK step is 8.47 mm and an EU step is 6.67 mm, the systems do not move in lockstep. One UK size is about 8.47 ÷ 6.67 = 1.27 EU sizes. A fixed offset such as 'UK plus 34' only holds over a limited range, and charts round the results in different ways.

Common offsets, and why to treat them as rough

Many charts for adults show roughly these relationships:

• US men's sizes are listed about one size above UK sizes.
• US women's sizes are listed about two sizes above UK sizes.
• A US women's size is commonly paired with a US men's size about one and a half sizes lower.

Brand charts differ from these, and a half size in either direction is common. Use the offsets to sanity-check a listing, not to decide a purchase. The shoe size converter handles US, UK, EU, Mexico, Canada, Australia, Japan, Brazil, centimeters, inches and mondopoint, which is useful for seeing how far the systems drift apart.

Worked example: from foot length to size

Stand on a sheet of paper with your heel against a wall, mark the tip of the longest toe, and measure from the wall to the mark. Measure both feet and use the longer one. Feet tend to be a little larger later in the day, so an afternoon measurement is safer.

A shoe's internal length is longer than the foot to leave room for toes. Guides commonly allow 1 to 2 cm. Multiplying by 1.5 then counts Paris points, since each point is two thirds of a centimeter.

EU size ≈ (foot length in cm + allowance) × 1.5A rule of thumb. The allowance, usually 1 to 2 cm, depends on the shoe style.

Example: a foot measures 10.25 inches. In centimeters that is 10.25 × 2.54 = 26.04 cm. With a 1.5 cm allowance, (26.04 + 1.5) × 1.5 = 41.3, so EU 41 is the likely fit. Using 1 cm gives 40.6 and 2 cm gives 42.1, so it is sensible to try 41 and 42 and see which feels better. The inches to centimeters converter does the first step, and the length converter covers other pairs of units.

Buying tips

• Check the brand's own size chart. If it lists foot length in centimeters or millimeters, compare your measurement with it directly rather than using a generic conversion.
• Leave about a thumb's width between your longest toe and the end of the shoe when standing, a common fitting guideline.
• Width matters as much as length. A shoe that is long enough but too narrow is still uncomfortable, and width labels differ between brands.
• If you land between sizes, size up and adjust with socks or an insole, rather than squeezing into the smaller size.
• Keep a note of sizes that fit in each brand. Your size in one brand is a better guide than any chart.

The same principle applies to garments: the article on clothing size conversion shows how to compare body measurements instead of labels.