Calculate Total Run

What happens in this clip

With the number of treads determined, calculate the 'total run' of your stairs. A standard tread depth is often around 10 inches. Multiply your number of treads (7 in the example) by your chosen tread depth (10 inches). This calculation (7 treads * 10 inches/tread) gives a total run of 70 inches. This figure tells you how far horizontally the stairs will extend from the deck.

Goal: Calculate the total horizontal distance the stairs will cover, known as the 'total run', by multiplying the number of treads by the desired tread depth.

What's used

Tools

• Calculator

About the full video

This video provides step-by-step instructions for accurately laying out deck stair stringers by calculating the total rise, determining the number of risers and treads, and then calculating the total run to find the precise landing point for the stairs. This method helps avoid common mistakes in stair construction.

Step 6 of 7: Determine the Total Run

Multiply the number of treads (from Step 5) by the desired tread depth. A common tread depth is 10 to 11 inches, but this can vary. Ensure the tread depth is consistent and meets local code requirements. For example, if you have 13 treads and a desired tread depth of 10 inches, the total run is 13 * 10 = 130 inches.

Open this step in the guide

Every video in How to Calculate How Many Stairs You Need

1. Step 1: Measure the Total Rise

   • 0:15–0:29 Measure Total Rise
   • 0:01–0:28 Measure Total Vertical Rise
   • 0:17–0:31 Measure Total Rise

2. Step 2: Determine the Ideal Riser Height

   • 1:03–1:44 Calculate Riser Height (Option 1)
   • 1:44–2:33 Calculate Riser Height (Option 2) and Verify Code Compliance
   • 4:32–5:10 Calculate Individual Riser Height

3. Step 3: Calculate the Number of Risers

   • 0:32–0:54 Calculate Number of Risers
   • 8:59–9:54 Calculate Number of Risers and Treads
   • 7:42–8:55 Calculate Number of Risers

4. Step 4: Recalculate Actual Riser Height

   • 1:03–1:44 Calculate Riser Height (Option 1)
   • 4:32–5:10 Calculate Individual Riser Height
   • 1:44–2:33 Calculate Riser Height (Option 2) and Verify Code Compliance

5. Step 5: Calculate the Number of Treads

   • 3:54–5:04 Calculate the Number of Treads and Understand the Logic
   • 0:54–1:13 Determine Number of Treads
   • 8:59–9:54 Calculate Number of Risers and Treads

6. Step 6: Determine the Total Run

   • 1:13–1:29 Calculate Total Run (this video)
   • 1:31–2:57 Calculate Unit Run and Total Run
   • 6:51–8:30 Calculate Total Run

7. Step 7: Calculate Tread Depth

   • 2:05–2:24 Calculate Individual Riser Height & Tread Depth
   • 9:54–10:28 Determine Tread Run and Total Run
   • 8:50–10:30 Calculate Risers, Treads, and Total Run