The advanced hand-held Construction-Math Calculator - the industry standard for construction-math calculators by Calculated Industries. With many new built-in solutions and expanded preference selections, it is easy to use. Work In and Convert Between any Building Dimension, including Metric Built-in Right-Angle Solutions Calculate Areas, Volumes, and Perimeters Complete Stair Layouts Roof, Rafter, and Framing Solutions Circular Calculations: Arcs, Circumference, Segments, and More The Construction Master Pro advanced construction-math calculator provides powerful built-in solutions and expanded preference settings. It's easy to use in the field or office. Get the job done right with fast, accurate answers. Perfect for completing layouts, bids, and estimates plus saves time, money, materials, and frustration. Available in both hand held and desktop models (plus $10.00).