The vertical distance between the lower floor and the upper floor.

External diameter of the staircase.

External diameter of the staircase column.

Number of steps that make up the staircase. The upper floor counts as a step.

Horizontal distance between two step nosings.
The going must be between 230 and 330 mm (9 and 13").
Its ideal value is 280 mm (11").

Angle of the steps.
The angle is a multiple of 360.

Angle of the landing.
Enables the adjustment of the angle of departure/arrival, as well as the headroom.

Angle between the first step and the upper floor.
The angle is greater than 360° if the staircase makes more than one complete turn.

Distance between the ceiling and the walkline at the stairwell.
The headroom must be greater than 1900mm (75") and its ideal value is greater than or equal to 2100mm (83").

Step thickness.
Enables the calculation of the headroom.

G + 2H = 590 to 650mm
G + 2H = 23.2 to 25.6"
G: going
H: Step height
Formula created by French architect François Blondel (1618-1686) verifying coherence between the step height and the going.
The ideal value is 630mm (24.8").

The vertical distance between two step nosings.
The height of the step must be between 150 and 200mm (6 and 8").
Its ideal value is 175mm (7").