Stair Tangent Dark is a mobile stair-building calculator designed for rough-frame carpenters and tradespeople who don't construct stairs every day but need reliable math and layout outputs when they do. The app calculates measurements for a wide range of stair types — straight and flared stringers, circular and elliptical stairs, winders and landings — and generates detailed layout data to eliminate cumulative math errors. With ellipse point plotting for X-Y layouts and dedicated routines for French and polygon winders, Stair Tangent Dark helps you check designs, speed up on-site layout, and produce accurate cutting dimensions.
Key Features
⭐ Stair Tangent Dark includes twelve dedicated stair calculators covering locked and unlocked tread widths, riser counts, 45° stringers, flared stringers and more.
⭐ Built-in circular and elliptical stair routines with ellipse point layout for X-Y plotting and arc radius calculations.
⭐ Specialized tools for French winders, polygon winders and stair landing height to produce full layout data from a few inputs.
⭐ Quick layout estimates: circular stair layouts in around 10 minutes and elliptical layouts in roughly 30 minutes when supplied with correct dimensions.
⭐ Eliminates cumulative math errors by generating the full set of measurements and cutting information from user-entered dimensions.
Advantages
✅ Stair Tangent Dark reduces calculation mistakes and gives you reliable numeric results for on-site layout and cutting lists.
✅ Speeds up the layout process for complex shapes, saving time when working with circular and elliptical stairs.
✅ Useful for occasional stair builders and rough framers who need a dependable tool to check hand calculations.
✅ Provides comprehensive data for multiple stair types so you can produce accurate layouts without recreating formulas by hand.
Disadvantages
❎ Not a replacement for the experience and judgment of a professional stair builder; seasoned builders may not need an app.
❎ Requires correct input dimensions and some familiarity with carpentry terms to produce useful results.
❎ Complex elliptical layouts still require setup time and careful plotting, with full layouts taking up to the estimated 30 minutes.
