To calculate the quantity of product to be ordered,the dimensions of the area to be paved/coated must be measured to obtain the “net” square meters of plates or slats needed, to which the percentage of “scrap” should be added. We always recommend adding a 10% scrap. In any case, when purchasing interior and exterior wall and floor covering products, our automatic calculators will kick in to tell you which products and quantities to add to your cart, for a complete floor of all the items you need.