The way to fill in the Amazon listing size depends on the type of product you are selling. If you are selling clothing, you need to use standardized size attributes, such as body shape, height, etc. If you are selling other products, you can use inches as the unit.

When adding variations, you need to add the size and color in the Size and Color menus respectively, and then fill in the following information. After entering all the information, click Save and finish.