Short description of RapidSketch-Floor Plan & Area Calculator 2.3: RapidSketch is the fastest and easiest to learn software for creating accurate floor plan layouts. Built for appraisers, insurance inspectors, flooring installers and anyone who needs to calculate the area and perimeter of a floor plan. Simply draw the floor plan in RapidSketch using the mouse or keyboard and the program will automatically calculate total square footage and perimeter.