Deck Stair Calculator

This Deck Stair Calculator helps users determine the optimal number of steps, riser height, horizontal run, stringer length, tread board count, and stair angle for their deck stairs based on custom input dimensions and preferences.

Use Our Deck Stair Calculator

Step-by-Step Guide to Using the Deck Stair Calculator

The Deck Stair Calculator is a useful tool for planning and constructing your deck stairs. Follow this step-by-step guide to make the most of the calculator and ensure the safety and accuracy of your stair design.

Step 1: Prepare Your Measurements

Before beginning, gather the necessary measurements for your staircase design. Ensure you have an accurate measurement of the total vertical height (rise) from the ground to the top of the deck.

Step 2: Enter the Total Rise

  • Locate the input field labeled Total Rise (inches).
  • Enter the total vertical height in inches. Make sure the value is between the allowed range of 0 to 240 inches.

Step 3: Determine the Run per Step

  • Find the input field labeled Run per Step (inches).
  • Enter the run measurement, typically between 10 to 11 inches. Ensure the value is within the range of 9 to 14 inches.

Step 4: Specify the Riser Height

  • Locate the field labeled Riser Height (inches).
  • Input the desired riser height in inches, keeping within the standard range of 6 to 7.75 inches.

Step 5: Input the Stair Width

  • Find the field labeled Stair Width (inches).
  • Enter the width of the stairs, ensuring it is at least 36 inches. Enter a value within the allowed range of 36 to 144 inches.

Step 6: Select the Tread Type

  • Move to the dropdown labeled Tread Type.
  • Select either “Standard Board (5/4 or 2x)” or “Composite Decking” based on your material preference.

Step 7: Review Calculation Results

Once all input fields are completed, review the calculated results:

  • Number of Steps Needed: Indicates how many steps your staircase will require.
  • Actual Riser Height: Provides the exact riser height for your stair design, rounded to three decimal places.
  • Total Horizontal Run: Displays the total length of the stair run in inches.
  • Stringer Length: Shows the length of the stringer, in inches.
  • Number of Tread Boards Needed: Estimates the count of tread boards you will need, minus one.
  • Stair Angle: Calculates the angle of the stairs in degrees.

Follow these steps carefully to design safe and compliant deck stairs. Adjust and re-enter input values if needed, and consult building codes to ensure compliance with local requirements.