Building Design Tools

Free building design calculators — lay out stairs with riser, tread and pitch checks against IRC, IBC and UK Part K, plus floor area for room planning.

3 tools

Stair Calculator

Lay out a flight of stairs from the floor-to-floor height: riser count and height, treads, total run and pitch, checked against IRC, IBC or UK Part K.

Also in Building Design

Tools from other categories tagged with Building Design

Area Calculator

Calculate area for rectangle, circle, triangle, trapezoid, or parallelogram — with the formula shown and a live labelled diagram. Free.

FAR Calculator

List each floor to get gross floor area and floor area ratio for a lot, compare it with the zoning FAR limit, and see how much floor space is still allowed.

Why These Tools

Every riser in a flight has to match, so a staircase is decided by the floor-to-floor height before anything else. Stair Calculator splits that height into equal risers near the size you aim for, then gives the treads, the run and the pitch and ticks them off against the US IRC and IBC or UK Approved Document K. A drawing of the flight shows whether it will fit the room.

Area Calculator is listed here too, for measuring floor plans made of rectangles, triangles and trapezoids. Paint, tile, brick and concrete quantities, roof slope and beam sizing are planned for this page.

Building Design Tools