LFA Stairs Pro vs Stair Stringer Calculator Pro

LFA Stairs is the professional carpentry and design tool for laying out staircases on the jobsite. Enter the total rise and width, and you immediately get the riser and tread layout, dimensioned CAD blueprints, an interactive 3D model, and a complete cut list with every piece measured. ELEVEN STAIR TYPES • Straight • L-shape left and right • Winder L-shape • 180° U-shape • Winder U-shape • Spiral / Helical • Floating Cantilever • Curved • Mono-Stringer • Open Riser WHAT YOU GET • Riser and tread layout with exact floor arrival height • 2D CAD plan: plan view, front and side elevations, fully dimensioned • 3D stair that you can rotate and zoom with your fingers • Detail card for each piece: cut length, cross section, bevel angles, bearing points, and fasteners • Complete cut list ready for the lumberyard • Stringers, risers, treads, landings, railing, and skirtboards RAILINGS Wood balusters, wrought iron, glass panels, stainless steel cable, horizontal slats, and industrial pipe. Baluster spacing is computed automatically and checked against the clear-opening limit. BUILDING CODES Calculations follow the International Residential Code (IRC): riser height (R311.7.5.1), tread depth (R311.7.5.2), walkline in spirals (R311.7.10.1), 4-inch sphere rule for balusters (R312.1.3), landings (R311.7.6), and handrail height (R311.7.8.1). The app alerts you when any dimension falls outside IRC limits. EXPORT AND SHARE • PDF report with full technical specifications and jobsite plans • 3D and CAD exports in OBJ, DAE, and DXF IN YOUR LANGUAGE AND UNITS English and Spanish. Inches and feet, or metric. WORKS OFFLINE Calculation, design, and 3D viewer do not require an internet connection. Your projects and dimensions are saved locally on your device. PREMIUM SUBSCRIPTION PDF and CAD exports are included in the optional subscription. All Results tabs can be viewed without a subscription. • Monthly and annual plans with prices shown in the app for your region. • A 7-day free trial may be available to eligible new subscribers. Subscription automatically renews through your Apple ID unless canceled in iOS Settings at least 24 hours before the end of the current period. Made by LFA Interiors and Construction LLC. Privacy Policy: https://lfa-legal.surge.sh/privacy.html Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Stair Stringer Calculator lays out a straight flight of stairs from three measurements and tells you how to cut the stringers — in carpenter's fractions, not decimals. Enter the total rise, the tallest riser you'll accept and your tread depth. You get the riser count and exact riser height, the tread count, total run, stringer length and stair angle, plus a to-scale drawing of the cut stringer. CUT IT RIGHT • Riser height is rounded so it never exceeds your maximum • The first riser cut is dropped by your tread thickness, so every finished step is equal • Framing square settings and the step-off distance along the board edge • Notch depth and the solid wood left under the notches (throat) for a 2x10, a 2x12 or any board depth • How many stringers to cut for your stair width, and their spacing • Type measurements the way you read a tape: 108 1/2, 9' 0-1/2", 7 3/4 CHECK IT BEFORE YOU CUT Every layout is checked, and the result shows what passed, not only what failed: • IRC R311.7: maximum riser 7-3/4", minimum tread 10", maximum rise of one flight 151", minimum width 36", nosing and handrail requirements • AWC DCA 6 deck-stair stringer limits: at least 5" of throat, a 6'-0" maximum span for cut stringers, stringers no more than 18" on center • The stride rule 2R + T for a comfortable stair (24–25 in; 590–650 mm per DIN 18065 when you work in millimeters) FULL CUT LIST AND PDF • Height, run and board-edge mark for every step • A PDF layout sheet with the drawing, cut list and code check for your crew or inspector • Unlimited history: reopen any saved layout with its drawing and checks INCHES OR MILLIMETERS Switch units any time. Inch results read like a tape measure, to the nearest 1/16". WORKS THE WAY YOU DO • All calculations run on your device — no account or sign-in required. • Calculations and saved history work offline on the job site • No ads. Usage reporting can be turned off in Settings • The app sends verified purchase records and feedback you choose to submit • English and Spanish interface SIMPLE PRICING The calculation, drawing and code check are free, and the free version keeps your 10 most recent layouts. One in-app purchase unlocks the full cut list, PDF export and unlimited history. No subscription. The formula sources are listed in the app: IRC 2021 Section R311.7, AWC DCA 6-15 Figures 28–29, and the stride rule. This app is a layout aid; always verify against the building code in force at your job site.