Determine Tread Run and Total Run

What happens in this clip

The speaker explains that his pre-manufactured stair treads are 11 1/2 inches wide. After deducting 1 inch for nosing (the overhang), the effective run for each tread is 10 1/2 inches. Multiplying this individual tread run (10 1/2 inches) by the 13 treads previously calculated gives a total run of 136 1/2 inches. This total run determines the horizontal space needed for the staircase.

Goal: Calculate the individual run per tread by deducting the nosing from the tread material's width, then multiply by the number of treads to find the total run required for the staircase.

What's used

Tools

• Tape Measure

Materials

• Pre-manufactured Stair Treads

About the full video

This video provides a detailed guide on planning and dimensioning a staircase, focusing on understanding building codes, measuring key components like total rise, total run, headroom, and selecting appropriate materials. It covers essential terminology, calculation methods, and practical considerations for ensuring a safe and compliant staircase installation.

Step 7 of 7: Calculate Tread Depth

Divide the total run (calculated in Step 6) by the number of treads (from Step 5). This gives you the actual tread depth. For example, if you calculated a total run of 130 inches for 13 treads, the actual tread depth is 130 / 13 = 10 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
   • 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 (this video)
   • 8:50–10:30 Calculate Risers, Treads, and Total Run