Stair Stringer Layout

A field calculator for cutting stair stringers — enter total rise and target riser height to get riser count, actual riser height, tread run, and stringer cut length with a side-view diagram, all in seconds. Whether you're building a deck staircase, a porch step, or a basement stairway, this app removes the guesswork of laying out stringers. No more trial-and-error math on scrap plywood. Key Features - Instant riser calculation: Enter total rise and target riser height to see valid riser count options within a safe range. - Stringer cut length: Automatically calculates stringer length using the diagonal run, with end-cut allowance built in. - Flush or open-top layout: Switch between flush top connection and open-top framing with one tap. - Bottom drop adjustment: Account for a concrete pad or sub-floor offset at the base of the stringer. - Side-view cut diagram: See a live diagram of the riser and tread layout as you adjust your inputs. - Recent calculations: Save up to 10 calculations locally and reload them for a new job. - IRC reference values: Quick-fill common building code riser height ranges — shown for reference only. Recommended For - Carpenters and deck builders cutting stair stringers on site - DIY homeowners building a porch or deck staircase - Contractors double-checking riser and tread numbers before cutting IRC/IBC values are shown for reference only. Always confirm riser and tread limits with your local building code and inspector before cutting — this app does not replace a licensed contractor or structural calculation.