How to Calculate and Construct Steps On a Slope

STEPS
In order to calculate how many steps are needed to traverse a slope, the following important pieces of information must be known. The RISE, which is the change in vertical elevation from the bottom to the top of the slope; the RUN, which is the horizontal distance between the beginning of your steps and where you want them to end; the TREAD, which is the top surface of the step and typically is 12 inches or greater from front to back; the RISER, which is the step height and, typically, is between 5 and 7 inches, with 6 inches being the most common and most easy to climb.

To determine how many steps are required, divide the total rise by your riser height. To determine the depth of each tread, divide the run by the number of steps calculated.

Steps On a Slope
Example:
If your risers are 6 inches, your total rise is 4 feet and your run is 10 feet, you would convert the rise to inches (4 feet x 12 inches = 48 inches). You would divide this by the riser height (48/6), and this gives you the total number of steps you will need, which is 8. To calculate the tread depth convert the total run to inches (10 feet x 12 inches = 120 inches). Then, divide this by the number of steps you calculated above (120/8) = 15 inch treads.

Steps can be made in a variety of ways from a number of different materials including concrete, natural stone, boulders, pavers, gravel, timbers, the choice is up to you and your imagination. When constructing stairs into a slope, you start at the bottom and, basically, cut into the hill, one step at a time. For the bottom-most step, you would excavate down a minimum of 6 inches to accommodate the class 5. This “trench” should extend several inches forward of the front of the step and far enough back into the hill so the next step can rest on it. This depth will be determined by the step product you are using and the tread depth you calculated using the formula above. The class 5 needs to be tamped every 2 inches as you layer it in. The only type of stairs that would not require class 5 would be those being constructed using flat stackable boulders. Their mass is such that the use of class 5 is not necessary.