Stair project planner

Describe the stair you are building and get every figure you need to build it — riser and tread sizes, a code check, stringer cuts, the floor opening, a cut list and scaled drawings.

Free to use, no account needed. Want to keep it? Save project asks you to sign in or create a free account (email or Google), then saves it.

Project name

Feet & inches Millimetres

Building code

1. The height to climb

Total rise (floor to floor)Lower finished floor to upper finished floor. If you measured on subfloor, enter the finishes below. Target riser heightA preference: the riser count has to come out whole, so the actual riser is close to this. Lower floor finish (optional)Flooring still to go on the lower floor. Upper floor finish (optional)Flooring still to go on the upper floor. The upper floor is the top step (the usual case). Untick only if a full tread sits level with the upper floor.

2. The space

Stair widthFinished width of the stair. Tread going (run) (optional)Leave blank and StepCalc picks the most comfortable tread for your riser. Space available for the run (optional)Horizontal length you have from the upper floor edge to where the bottom step can land. Gives you every layout that fits. Upper floor depth (joists + subfloor)Joists plus subfloor plus ceiling at the stairwell. Sets the floor opening needed for headroom. Floor opening you have (optional)The length of the hole in the upper floor, if it is already framed.

3. Materials (stringers, treads, risers, balusters)

Stringer stock Stringer spacing (max)Most codes and tread makers want stringers no more than 16″ (400 mm) apart. Tread thicknessSets how much the bottom of the stringer is dropped. Nosing overhang (optional)How far each tread overhangs the riser below. Riser board thickness (optional)Leave blank or 0 for open risers. Baluster width (optional)For baluster spacing on an open side.