This is an easy calculator to determine the rise:
RISE: the height of one step in a staircase. This is the amount of vertical distance one moves when stepping from one stair tread onto the next. The rise should be between 5" & 7.5" with the ideal rise for a residence being 7".
and the run:
RUN: the horizontal distance of one stair. It is how far in, the stair goes which gives the amount of room for a persons foot. The run should be between 8.5" and 14". An intermediate run is 11". The stair tread is the RUN plus the nosing. Per most Building Codes, the tread should be between 9.5" and 14". An intermediate tread is 12".
of each step and the length of the boards needed for the stair stringers.
Numbers can be entered with a decimal or fraction (i.e. 8.0625 or 8 1/16).