Deciding the Width of Steps

• Decide how wide your want your staircase before you purchase the boards. Although the width of your steps may be determined by the area you have available, step width is often a personal preference. The width of your staircase affects everything from the number of stringers you need to hold the staircase up to the length of the plank boards that typically make up the stair treads. Place a stringer approximately every 12 inches under the steps during your initial step installation for optimal support.
  
  

Figuring the Run

• Before you can beginning building your steps, you'll need to figure the run -- or how high the steps will reach from the ground to the top of the stairs. To figure out the run for your steps, place a basic board on the floor of your porch. Let the end of the board hang straight off the edge of your porch where you plan to put the steps. Put a brick on the end of the board, if needed, to hold the board in place. Measure from the bottom of the board to the ground. This is the run of your steps.
  
  

Figuring the Rise

• The rise of the step is the difference from the surface of one step to the step above it. Although the typical rise for a pre-made step is 7 inches, this figure varies when you build custom steps based on the run you're covering with the steps. To figure out the rise of your steps, take the total run figure you measured and divide it by 7. If you get a whole number, this is the rise of each individual step. If you get a decimal point, round the sum of this equation down, and divide your run figure by the new rounded number. This will give you the actual rise for each step.
  
  

Cutting Stringers

• The stringers are the base or supports that fit underneath your steps. Purchase stringers already cut from the home improvement stores based on your run and rise figures, or create your own from 2-by-12 boards. If you choose to create your own stringers, use a a framing square fit with stair gauges to cut out triangular pieces from the stairs to make the stair step pattern. Mark where you intend to cut before cutting the stringer with your circular saw to avoid making any errors. To keep the rise of the stair accurate, cut away some of the top of the stair where the tread will sit based on your tread boards. For example, if you're using 2-by-6 boards to form your treads, you'll need to cut away approximately 1 1/2-inches from the top of each stair to keep the rise close.