Stair and Angle Calculator

About

Stair and Angle Calculator gives tradespeople and DIYers six precise calculators in one clean, fast app. No clutter, no subscriptions — just the numbers you need on site. STAIRS Enter total height, total run, and maximum step height. The app works out the number of steps, exact riser height, and going, accounting for optional top and bottom landings. ROOF Calculate rafter length, ridge height, and roof area. Work by pitch angle or by rise — enter your total span and the app does the rest. Add roof depth to get surface area for materials. TRIANGLE Solve any right-angle triangle. Enter two of the three sides (A, B, or hypotenuse C) and get the missing side, both angles, and area instantly. AREA Switch between rectangle and circle modes. Enter length and width for area, or add height to get volume — useful for concrete, soil, or fill calculations. Circle mode gives area and circumference from a radius. CIRCLE Go deeper with circle geometry. Enter a radius and optional arc angle to calculate arc length, chord length, and sector area — useful for curved walls, arches, and landscaping. ROOM Plan paint, tiles, and flooring for any room. Enter length, width, and height, then specify the number of doors and windows (or a total opening area) to get net wall area automatically deducted. UNITS All calculators support mm, cm, m, and ft. Switch units at any time using the ruler button — inputs convert instantly. Simple, reliable, and built for real work.