To accurately compute the area of an individual solar panel, one must multiply the length by the width. What is “layout factor” and why does it matter? The layout factor scales the raw module footprint to include spacing for shade clearance, walkways, access paths, parapets, setbacks and BOS. Knowing the dimensions of the panels is essential, as most solar panels have standard. This Solar Panel Area Calculator helps homeowners, installers, and designers quickly estimate how much roof or ground area a set of solar panels will cover based on the panel length, panel width (in inches), and number of panels. The result is expressed in square meters as the Total Area. Gather necessary measurements, 3.