The adults Crocs Classic Clog is roomy fit Crocs style.
The way Crocs are designed to fit is slightly different from other shoes. They should have a loose fitting, so you should have space between the sides of your feet and plenty of space for your toes.
IMPORTANT - As Crocs are original from the U.S.A the size details prominently displayed on the soles of all Crocs footwear are the US shoe size. Crocs do not mark their shoes with UK or EU sizes, these sizing details can be found on the green labels attached to the left shoe.