In the United States, flooring is measured in either square feet or square yards. To measure square feet, a person should multiply the length of the room by the width.
Many retailers, such as Lowe's, have calculators on their websites that allow homeowners to enter the room's measurements. The calculator then gives the square footage and square yardage of the room.
These measurements are only an estimate. About 10 percent more flooring should be purchased than the measurements indicate, just to be on the safe side. For instance, if the calculator indicates 100 square feet of carpet is needed, a homeowner should buy 110 square feet.