How sizing is listed
Every listing shows the size exactly as printed on the shoe label, followed by the US, UK and EU conversions. Where a shoe is a youth or grade-school size, that is noted alongside the women's equivalent.
Conversions
Conversions are taken from the manufacturer's own size chart, not estimated. If a listing shows more than one size system, the first one is the label size and the rest are conversions.
Measuring your foot
Stand on a sheet of paper against a wall, mark the tip of your longest toe, and measure from the wall to the mark. Add 5–10 mm for comfort. Compare that length to the insole measurement where one is listed.
Fit notes
Some models run small or large. Where the listing description notes a fit quirk, trust it — it comes from trying the pair on.