Shoe Size Converter (UK/EU/US)

UK shoe sizes use a different scale from US and EU sizes. UK sizes start from 0 for infants and increase in increments of one-third of an inch (8.47 mm). EU sizes follow the Paris point system, where each size is 6.67 mm. US sizes are offset from UK sizes by approximately 1 for men and 2 for women, which is why a single pair of feet can carry three quite different numbers depending on where the shoes were made.

Half sizes are supported throughout, and the tool covers men's, women's and children's ranges in all three systems. It also shows the matching foot length in centimetres, which is the most reliable way to find your size when you cross between them. In round terms a UK 6 lands on EU 39-40, US men's 7, US women's 8.5 and JP 25cm, while a UK 7 becomes EU 40-41, US men's 8, US women's 9.5 and JP 26cm.

Further up the scale a UK 8 corresponds to EU 41-42, US men's 9, US women's 10.5 and JP 27cm, and a UK 9 to EU 42-43, US men's 10, US women's 11.5 and JP 28cm. Each whole UK or US size adds 8.5mm, one third of an inch, whereas EU sizes step by roughly 6.67mm because the Paris point is 2/3 cm. Children's numbering restarts, so a UK children's 13 sits just below a UK adult 1, around EU 31-32.

To measure at home, stand barefoot on a sheet of paper in the evening, once your feet have swollen slightly, and mark the heel and the longest toe. Measure heel to toe in millimetres. Your UK size is (length mm − 23.85) ÷ 8.46, and the EU size is roughly the length in centimetres × 1.5. Width deserves the same attention as length, so measure across the widest part of the ball. UK widths run E for medium, F for wide, G for extra wide and H, the equivalent of a men's 4E. Most high-street shoes come in E only, while Clarks and Hotter stock F to H.

Trainers rarely behave like formal shoes. Most brands suggest going up half a size, but the direction of the error depends on the maker. Nike runs slim, the Adidas Stan Smith is true to size, New Balance runs wide enough that many people size down, and Converse comes up a full size large. Running shoes want about 1cm of toe clearance so the foot does not slam forward on descents, which usually means half a size above your walking size. Football boots are deliberately tight for ball feel, and cycling shoes tighter still.

Children's feet move quickly. Between birth and three a child gains about 2 shoe sizes a year, slowing to 1 size a year from four to seven, then slower again. Shops such as Clarks and Start-Rite will gauge school-age feet free of charge, and every 8-12 weeks is a sensible interval. Leave 1cm of room at the front, about a thumb's width, with the child standing. Handing down well-worn shoes is a poor idea, because the insole has already moulded to another foot. As a rough guide, a one-year-old is often a UK 4, a three-year-old a UK 8, a five-year-old a UK 11, and by seven many children have reached UK 1 and the start of the adult range.

Specialist footwear follows its own rules. Walking boots usually go half a size up to allow for thick socks and the swelling that comes with a long day out. Ski boots feel very tight at first and mould to the foot, though hired pairs are often an inexact fit. Football boots frequently go half a size down from your trainer size, while steel-toe safety boots need a full size up because the construction is bulkier. For a wedding or other formal occasion, stay at your regular size and wear thin socks or stockings. Bunions and hammer toes call for the wider UK E to H fittings, which is where Clarks Wallabees, Hotter and Footglove earn their keep.