To convert feet to square feet for a rectangular area, find the length of the area you are measuring, and multiply it by the width of the area. A square foot is a measurement unit equal to a square that measures one foot on each side.Continue Reading
Use a ruler or a tape measure to measure the length of the rectangular area in feet.
Measure the width of the rectangular area in feet.
Determine the square footage of the rectangular area by multiplying the length by the width. For example, a rectangular area that is 5 feet long by 2 feet wide has an area of 10 square feet.