Calculate Number of Risers

What happens in this clip

Practice calculating the number of risers required for a given floor-to-floor height. For example, if the floor-to-floor height is 3300mm and you aim for a rise of 190mm, dividing 3300 by 190 gives approximately 17.36 risers. Since risers must be of equal size for comfortable use, you cannot have a fractional riser. Instead, round the number of risers (e.g., to 17 or 18) and then divide the total height by the chosen number of risers to get the exact uniform rise dimension for each step. It is crucial to always mention the total floor-to-floor height along with the number of equal parts (risers) when dimensioning, rather than just stating the individual riser height.

Goal: Learn how to accurately calculate the number of risers for a given floor height, ensuring comfortable and equal step sizes.

What's used

Tools

• Calculator Any
• Whiteboard Marker Whiteboard
• Pen
• Whiteboard/Paper

About the full video

This project provides a foundational understanding of staircase components, design principles, and their representation in architectural plans. It covers essential terminology, dimensional calculations, common staircase types, and the importance of building codes for safe and functional staircase design in DIY or professional contexts.

Step 3 of 7: Calculate the Number of Risers

Divide the total rise (from Step 1) by your chosen ideal riser height (from Step 2). Round the result to the nearest whole number. This will be your number of risers. For instance, if your total rise is 100 inches and you aim for a 7-inch riser height, 100 / 7 = 14.28, which rounds to 14 risers.

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 (this video)

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
   • 8:50–10:30 Calculate Risers, Treads, and Total Run