Linear feet is calculated by adding the lengths of points connected by straight lines. For example, the perimeter around a house can be measured in linear feet. Square feet measures area, and linear feet measures length.
Two areas that measure the same square feet can have different perimeters, hence differing values for linear feet, if they’re shaped differently. For example, a rectangle that measures 8 feet long and 2 feet wide has an area of 16 square feet (length x width) and a perimeter of 20 linear feet (2 x (length + width), while a square that measures 4 feet by 4 feet has the same area but a perimeter of 16 linear feet.