Calculating stair rise and run is an essential part of designing safe and functional stairs. Incorrect calculations can lead to uncomfortable and potentially dangerous steps. By understanding the basic principles behind these calculations, you can ensure your stairs are both comfortable and safe.

Step 1: Understand the Terminology

Before calculating stair rise and run, familiarize yourself with these basic terms:

– Stair Rise: The height of each individual step, measured vertically.

– Stair Run: The horizontal distance of each step, measured from where the tread begins.

– Total Rise: The overall height from the floor at the start to the floor at the end of the stairs.

– Total Run: The overall horizontal length of the staircase.

Step 2: Determine Total Rise and Total Run

Measure the vertical height (Total Rise) from where your stairs begin to where they end. Next, measure the horizontal distance (Total Run) between these two points to accurately calculate stair rise and run.

Step 3: Comply with Building Codes

Consult your local building codes for specific information on allowed stair rise/run dimensions. These codes help ensure a safe walking experience for users. A common industry standard is a maximum rise of 7 inches (175mm) combined with a minimum run of 11 inches (280mm).

Step 4: Calculate Stair Rise

Once you have your Total Rise measurement, divide this number by the desired number of steps. For example, if your Total Rise is 100 inches and you want 14 steps:

Stair Rise = Total Rise / Number of Steps

Stair Rise = 100 inches / 14

Stair Rise = 7.14 inches per step

Step 5: Calculate Stair Run

Now it’s time to determine the Stair Run. Simply divide your Total Run measurement by one less than the number of steps. Continuing with our example:

Stair Run = Total Run / (Number of Steps – 1)

Stair Run = 225 inches / (14 – 1)

Stair Run = 225 / 13

Stair Run = 17.31 inches per step

Step 6: Adjust Calculations if Necessary

If your calculated stair rise and run do not adhere to the building codes, you may need to adjust your calculations. For instance, if your Stair Rise exceeds the code limit, you could consider increasing the number of steps, thus reducing the height of each step.

Conclusion:

With the right knowledge and a careful approach, calculating stair rise and run is a simple process. Not only will this ensure that your stairs comply with local building codes, but it will also guarantee that they are comfortable and safe for all who use them.