Sizing can be found down the bottom of the description for each item. This is done because each item may vary in sizing so this way sizing can be more accurate for the item you are wishing to buy.
To find the sizing on a desktop click on the garment you are looking at and on the right hand side you will find the product description. Scroll down a little and you will find 'Measurements'
To find the sizing on a mobile click on the garment you are looking at and scroll down. You will find the product description here then down the bottom of that you will find the 'Measurements'