Something that is 600 square feet could be 20 feet by 30 feet, 24 feet by 25 feet, 600 feet by 1 foot or any other combination of length times width that equals 600. A square foot is the area of a square that is 1 foot by 1 foot. Square footage is the measurement of area that equals the amount of square feet it would take to cover it.
Square footage is used to measure surface area rather than volume. It is used in real estate to measure a wide variety of things, such as individual rooms, rugs, flooring, counters and the total area of buildings. It is used in the calculation of taxes, such as when deducting costs associated with the square footage of a home office compared to the total square footage of a home. It is also used when ordering building materials and calculating their costs, and it is used when measuring walls and ordering the correct amount of paint needed to cover them. It is used to analyze, predict and compare energy usage among buildings.
Similar measurements are the square yard, which is commonly used to measure cloth. This measurement is also applied to acres, which are equivalent to 43,560 square feet and used for measuring large areas of land.