[HayZee518]

your total rise is 99 3/8" - divide this number by 7 1/2 to get the number of risers or steps - in this case = 13.25. round off to next whole number or 13 rises. your run is 97.5 inches - divide this by 10 1/2" which is nominal tread width = 9.29 minus the bullnose. what all this amounts to be is a bunch of right triangles (steps) set within another right triangle (the whole stringer) you use a framing square to figure out your cutting lines on a 2X12. Risers can vary from 7.5" to 8" but no more. widths can be a minimum of 10.5 inches to 11 inches.