UK Size Conversion Table

To convert a foot measurement in cm to a UK shoe size, start by measuring the foot from the back of the heel to the tip of the longest toe in centimetres — standing up, on a hard floor, at the end of the day when feet are at their largest. Once you have that measurement, use the conversion table above to find the corresponding UK shoe size.

The size shown accounts for the recommended growing room of around 0.8–1cm, so the internal length of the shoe will be slightly longer than the bare foot measurement. For example, a foot measuring 12.2cm typically corresponds to a UK size 4 in children's shoes.

Always measure both feet and fit to the larger — it is more common than you might think for feet to differ slightly in length. For the most accurate result, cross-reference your cm measurement with the individual brand's own size chart, as internal shoe lengths can vary slightly between manufacturers.

UK and EU shoe sizes use entirely different measurement systems, which is why they do not convert in a simple 1:1 ratio. The UK system is based on the barleycorn — a historical unit equal to one-third of an inch — while the EU system uses Paris points. As a rough guide, EU sizes run approximately 33–34 sizes ahead of UK sizes: for example, UK 5 is roughly EU 38, and UK 8 is roughly EU 42. For children, a UK 1 Junior is approximately EU 33, and a UK 4 Junior is approximately EU 37. However, this is not an exact conversion and can vary between brands, so always check the specific brand's own size chart alongside any conversion table for the most accurate fit.

UK and US shoe sizes both use the barleycorn system but start their numbering at different points, so they are close but not identical. For men's shoes, US sizes are approximately half a size larger than UK — so a UK 8 is roughly a US 8.5. For women's shoes, the gap is larger: US women's sizes are approximately two sizes above the UK equivalent, so a UK 5 is roughly a US 7. For children's shoes, US sizes are typically half a size larger than UK — a UK 4 (infant) is roughly a US 4.5. These differences make it particularly important to check size charts when buying from US-based brands, as assuming the same number will fit can result in shoes that are noticeably too large or too small.

Measuring your child's feet at home is quick and straightforward. You will need a hard floor, a piece of paper, a pencil, and a ruler or tape measure. Ask your child to stand on the paper with their heel against a straight edge such as a wall. Draw a line at the tip of their longest toe — which is not always the big toe — then measure from the straight edge to that line in centimetres. Repeat for the other foot and use the larger measurement. Always measure at the end of the day when feet are at their largest, and with the socks your child normally wears. You can then use the conversion table on this page to find the right UK shoe size. Happy Little Soles also offersSizeWise— a phone-based measuring tool that guides you through the process step by step using just your smartphone.

This is one of the most common questions parents have when first navigating children's shoe sizing — and it is entirely understandable, as it looks like a mistake but is actually intentional. UK children's shoe sizes are split into two separate ranges: infant sizes, which run from 0 up to 13, and junior sizes, which restart at 1 and run up to around 6 or 7 before meeting adult sizing. The reset exists because the two ranges were historically designed as distinct scales for different foot sizes. Importantly, a UK 13 (infant) and a UK 1 (junior) are not the same size — a UK 1 Junior is one size increment larger than a UK 13 infant. At Happy Little Soles, sizes are clearly labelled on every product — for example, UK 13, UK 1 Junior, and UK 4 Adult — so you can always tell at a glance exactly which range a size belongs to.