Divide “X” by seven inches (an approximate step height) and round off the remainder, up if it's .5 or more, or down if it's less than .5. That will give you an approximate number of stair risers. The ...
Stairs that have a 7.5 inch riser and a 10 ... The tread keeps getting shallower as the riser height increases. You can see how this theory and formula translates to ladders and step ladders.