The Stair page of the Properties contains parameters for defining the size of treads and risers.
Stair shape and Turn type: These vary depending on the type of stair you are creating. These options are explained for each stair type.
Base Width: The width of the stairs. You can define this here, or when defining the stair geometry.
Tread depth: The horizontal depth of each step.
Riser height: The vertical height of each step.
Riser count: The number of stairs. You can define this here, or when defining the stair geometry.
Terminate with: Defines what will appear at the top of the stairs.
Note: Other stair properties, such as tread and riser thickness, nosing length, and materials can be set using the Style Manager. See Stairs Styles. Once you have styles defined, you can set a stair's style in the General page of the Properties.