Calculate risers, treads, stringer length and angle, then check them against IRC, IBC, UK Part K, Eurocode or the Australian NCC — and download a complete build packet PDF.
Most tools give you arithmetic any chat bot can do. These two carry their weight on the job site and at the permit desk.
Pick a jurisdiction and edition. Every riser, tread, headroom and width limit re-checks live, with the exact clause cited. Competitors are locked to one stale IRC edition.
One PDF with the spec sheet, cut list, framing-square setup (exactly where to clamp the stair gauges), and a materials list — plus a link that re-opens the calculator pre-filled.
From a basement straight run to a helical staircase — each with live drawing, code check, and printable output. Here are the essentials; see all 32 →
Rise, run, stringer, angle, mount type.
Grade-to-deck, stringer spacing, landing trigger.
Quarter-turn with landing solver.
Switchback, stairwell footprint, turn headroom.
Pie-tread geometry, per-tread code check.
Arc treads, center column, handrail length.
Pour volume, formwork, rebar estimate.
Slope & single-step quick utility.