((Length in Inches) x (Width in Inches)) ÷ 144 = Area in Square Feet (Area in Square Feet) x (1 + Waste Factor %) = Total Square Feet to Order Note there are a number of variables to determine waste factor or the overage that are unique to the type of product you are installing. Also scenarios particular to your technique, tastes, preferences, size, and patterns of install can change the yield of the product significantly. For a more in depth explanation you should click and read this article to be aware of some things to consider when calculating how much material to order.