How Do You Use a Square Footage Calculator to Measure a Room?

To use a square footage calculator to measure a room, first find its length and width measurements, either in feet or feet and inches. Input the measurements into the corresponding boxes of the calculator, and then hit Calculate. For example, using the calculator on Green Home Solutions' website,, a room 10 feet wide and 120 feet long has an area of 120 square feet.

Some square footage calculators let you estimate the square footage needed for flooring materials such as hardwood or tile. These calculators include a percentage waste factor. The calculator sometimes presets this factor, which is typically about 5 or 10 percent. Certain devices permit you to input any percentage you select.

For instance, on's online square footage calculator, you are able to input your choice of waste percent. For a 120-square foot room with 5 percent waste allowed, you should buy 126 square feet of flooring. With 10 percent anticipated waste, buy 132 square feet.

If you are installing a pattern that requires different sizes of flooring, certain square footage calculators show you how many square feet of each to buy. On the calculator at, first determine the total square footage of the room. Then indicate the width of each type of flooring you plan to use. The calculator displays the required amount to purchase, including a 5 percent waste factor.