Shoe Size Converter
Equivalent sizes
EU 42.5
Shoe sizing is a convention rather than a standard, and the same nominal size varies between brands. Foot length in centimetres is the most reliable guide — measure your foot and compare against that column.
Four scales that do not quite line up
Buying shoes from another country means translating between systems that were never designed to agree. This converter takes a size in US, UK or EU numbering, or a foot length in centimetres, and shows the equivalent in all four across separate men’s and women’s charts.
A worked lookup
A men’s US 9 is a UK 8.5, an EU 42.5, and corresponds to a foot about 26.7 cm long. A women’s US 8 is a UK 6, an EU 39, and about 24.1 cm. Enter 27 cm on the men’s chart and it returns US 9.5, UK 9, EU 43.
A value well outside the chart is rejected rather than snapped to the nearest row. Entering a US 30 does not quietly return the largest size available; it tells you the value is outside the chart, which usually means the wrong scale is selected.
Two patterns fall out of those numbers. UK men’s sizes run about half a size below US men’s throughout the range, a legacy of the two countries measuring from different starting points. And the men’s and women’s US scales are offset: a men’s US 8 is about 25.7 cm while a women’s US 8 is about 24.1 cm. On these charts a women’s 8 and a men’s 6 share that 24.1 cm length, a two-size gap, though 1.5 is the figure more commonly quoted — another reason to compare centimetres rather than numbers.
How the lookup works
Each chart is a table of rows, and every row carries the size in all four scales. The converter finds the row whose value in your chosen scale is closest to what you entered, then reads the rest of that row across. Because half sizes and brand variation mean an exact match is the exception rather than the rule, a near match is shown as the closest size rather than being refused.
The bounds check allows one average step of slack past either end of the chart, so a size just off the table still resolves to its neighbour while a wild value does not. That is what stops an EU number typed while the scale still says US from being dressed up as an approximate answer.
Why no chart can be exactly right
Shoe sizing is a convention rather than a standard. There is a European standard — the Mondopoint system, which simply states foot length and width in millimetres — but almost nobody sells shoes in it outside military and ski boot fitting. Everything else is inherited practice, and the increments differ: a full UK size is a third of an inch, while EU sizes step in two-thirds of a centimetre, so the two scales drift against each other rather than mapping cleanly.
On top of that, the last — the form a shoe is built around — varies by brand and by model within a brand. Two shoes labelled the same size from the same maker can fit differently if one is a running shoe and the other a boot. Width is a separate dimension that most numbering ignores entirely. Treat any conversion, including this one, as a starting point, and check the maker’s own chart before ordering.
Shoe sizing questions
How do I measure my foot properly?
Stand on a sheet of paper against a wall, in the socks you will wear, and mark the tip of the longest toe — which is not always the big toe. Measure heel to mark in centimetres, do both feet, and use the larger. Measure late in the day, when feet are at their largest.
Why does the same size fit differently between brands?
Because each brand builds on its own lasts and applies the numbering to them by house convention. There is no body enforcing consistency, which is why foot length in centimetres, compared against the specific brand’s own chart, is the only reliable approach.
Should I size up for running shoes?
Usually by about half a size. Feet swell during exercise and the toes need room to move forward on landing, so the common guidance is a thumb’s width at the end. That is a fitting convention applied on top of whatever this chart returns.