About
StairSmith is a free online staircase designer that runs in the browser. No account, no download, no setup: open the page and start building stairs.
It covers timber staircases in three arrangements: straight flights, quarter turn stairs on a single winder, and half turn stairs on a double winder. Set the floor to floor height, then adjust rise, going, width and the shape of each kite. The 3D stair creator redraws as you change them, so trying a steeper pitch or a deeper kite costs nothing but a second. Rise, going and pitch stay on screen throughout, which makes it an online staircase calculator as much as a modeller.
The geometry follows how stairs are actually built. Newel posts, stringers, balustrade and kite winders, set out the way a joiner would set them out, rather than an abstract ribbon of treads floating in space.
Finished designs export as IFC4X3 for BIM coordination, or DXF for plans, elevations and sections you can take into CAD and develop further. Most free stair builders stop at a picture and a price. This one hands you a parametric staircase model and gets out of the way. Everything it produces is yours to use, and it is a conceptual design tool, so the setting out still wants checking before anything is cut.