User Guide
Learn how to use the stair calculator and understand all input parameters.
Basic UsageParameter
The stair calculator helps you determine the optimal dimensions for your staircase. Simply enter your total height and total run, and the calculator will compute the number of steps, rise, and run for each step.
Calculation ModesParameter
Choose from three calculation modes: Auto (optimal calculation), Fixed Steps (specify number of steps), or Fixed Riser (specify riser height).
Total HeightParameter
The vertical distance from the bottom floor to the top floor. Measure from finished floor to finished floor.
Total RunParameter
The horizontal distance the staircase will cover. This is measured from the face of the first riser to the face of the last riser.
Number of StepsParameter
(Fixed Steps mode only) Specify the exact number of steps you want in your staircase.
Riser HeightParameter
(Fixed Riser mode only) Specify the height of each step. Standard residential risers are typically 7-8 inches.
Tread ThicknessParameter
The thickness of the tread material (usually 1-1.5 inches for wood). This affects the actual rise calculation.
HeadroomParameter
The minimum vertical clearance above the stairs. IRC requires at least 80 inches (6 feet 8 inches).
Floor ThicknessParameter
The thickness of the upper floor structure. This is added to the total height for accurate calculations.
Floor OpeningParameter
The dimensions of the opening in the upper floor. The calculator will verify if your staircase fits within this opening.
Number of StepsParameter
The total number of steps (risers) in your staircase. This includes the step up to the landing.
Riser HeightParameter
The vertical height of each step. All risers should be equal for safety.
Tread DepthParameter
The horizontal depth of each step (run). This is where you place your foot.
Stringer LengthParameter
The length of the diagonal support beam (stringer) needed for your staircase.
AngleParameter
The angle of the staircase from horizontal. Typical residential stairs are 30-35 degrees.
Comfort FormulaParameter
The result of 2×Rise + Run. Ideal range is 24-25 inches for comfortable stairs.