How To Measure Countertops In Square Feet. (length x width = area). To measure existing countertops, measure the length and the width in inches, then multiply those measurements to find the area in square inches.
Find the square footage of a space that's almost regularly shaped. Use a straightedge to draw a line to mark off the edges of each box with a pencil or a piece of chalk. To measure existing countertops, measure the length and the width in inches, then multiply those measurements to find the area in square inches.
Divide the total area in inches by 144 to get the area in square feet.
Divide your countertop into runs or rectangular boxes. Start at one end and measure each straight segment of countertop. For example, the length of your countertop is 100 inches. So, 44 inches times 26 inches yields 3,744 square inches.