EU 28 lands near age four or five, where a large Austrian study of 858 children found 69 percent were wearing street shoes too short for their feet.
CM to UK conversion
Centimetres to UK kids' sizes hold near an 8-number gap until the UK scale resets at a 220 mm foot, where the same length suddenly reads about 21 less: 18 cm is UK 10 but 22 cm is UK 1. Sizing by the millimetre length sidesteps the confusion the reset causes. Because a shoe's inside often measures shorter than its printed size, checking the internal length against the foot matters more than the UK number itself.
At this size, CM to UK
One size up from 17 cm, UK moves 0.5 to UK 9.5 while the metric length rises 0.5 to 17.5 cm. Both 17 cm and UK 9 are whole numbers here, so nothing rounds. For 17 cm, the UK column here runs UK 8.5, UK 9, UK 9.5, stepping a half size at a time.
Foot length vs shoe length
A CM shoe size is your measured foot length, not the space inside the shoe.
Brands add 0.5 to 1.0 cm of toe room so your toes clear the front. Japanese cm
labels already include about 1 cm of it, so a JP 24.0 measures near 25 cm
inside; an EU number instead describes the last. That built-in gap is why
conversion tables disagree.
Why one foot length gives many sizes
Size Chart CM EU US UK 15.5 25 8.5 7.5 16 26 9 8 16.5 27 9.5 8.5 17 28 10 9 17.5 28.5 10.5 9.5 18 29 11 10 18.5 30 11.5 10.5
Frequently Asked Questions Does 17 cm round up or down in UK? The finding argues for rounding up and checking fit often: a foot at this stage adds about 1 mm a month, so today's perfect length is next season's pinch.
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Note Kids sizes transition to adult sizes around EU 38 / US 5 Children's feet grow rapidly - remeasure every 3-4 months Allow 10-15mm growing room when fitting Shoe sizes can vary by brand and style See a number that looks off? Report an error on this page.