The Construction Master Pro Desktop is easy to use on the jobsite or in the office and is perfect for completing layouts, bids and estimates. It is the most complete construction-math calculator on the market. It will help you save time, reduce costs and prevent re-work. Work in and convert between metric and feet-inch-fractions. Instantly calculate complex construction challenges for stair layouts, roofs, framing and much more. Full trigonometric functions with sine, cosine, tangent, arcsine, arccosine and arctangent.