Shoe size in the United Kingdom, Ireland, India, Pakistan and South Africa is based on the length of the last used to make the shoes, measured in barleycorns (1⁄3 inch) starting from the smallest size deemed practical, which is called size zero. It is not formally standardised. The last is typically longer than the foot heel to toe length by 1⁄2 to 2⁄3 in or 1+1⁄2 to 2 barleycorns, so to determine the shoe size based on actual foot length one must add 2 barleycorns.
A child's size zero is equiva...
