Stair Riser Count from Total Rise

Every stair starts here. Measure the total rise from finished floor to finished floor, not subfloor to subfloor, then divide by the riser height you are aiming for. An 8 ft basement rise at a 7 in target gives $96/7 = 13.71$ risers, which is the calculator telling you the truth rather than the answer. You cannot build 0.71 of a step, so you round up to 14 and divide back: $96/14 = 6.857$ in, a hair under 6$\ frac{7}{8}$ in per riser. Rounding down to 13 would give 7.38 in, which busts most residential codes.

Those codes are why the target matters. The IRC allows a maximum 7$\ frac{3}{4}$ in riser for private stairs; the Ontario and national Canadian codes cap private risers at 200 mm; commercial and public stairs are tighter still. Just as important is the uniformity rule: the tallest and shortest riser in a flight may differ by no more than about 3/8 in (roughly 10 mm). That is a trip-hazard rule written in blood, and it is the reason you divide the rise evenly rather than making the last step take up the slack.