The Stair Calculator with Landing Turn is an essential tool for architects, builders, and homeowners alike. It simplifies the intricate calculations required to design stairs that are both safe and compliant with building regulations. By inputting specific parameters such as the total rise and desired number of steps, the calculator provides critical dimensions including step rise, tread depth, and landing dimensions. This ensures the construction of a staircase that is not only safe but also optimizes space efficiency and user comfort.
Formula of Stair Calculator With Landing Turn
Understanding the stair calculator’s functionality requires familiarity with the formulas it employs:
1. Straight Run Calculations:
- Total Rise (H): The vertical distance between the start and end floor levels.
- Number of Steps (N): The total rise divided by the desired step rise, usually between 6 inches to 7 inches.
- Step Rise (R): The total rise divided by the number of steps (H / N).
- Tread Depth (G): The horizontal distance between the front edges of two consecutive steps. Building codes typically mandate minimum tread depths, usually around 10 inches to 11 inches.
2. Landing Dimensions:
- Landing Width (W): The minimum width should facilitate comfortable passage. Building codes often mandate a minimum width equal to the stair tread depth (G).
- Landing Length (L): This depends on the turn type and available space. For a 90-degree turn, the length (L) should be at least equal to the sum of the tread depth (G) and the step width (W).
3. Turn Calculations:
- Quarter-turn Landing: Involves a 90-degree turn. The diagonal length (D) of the landing can be calculated using the Pythagorean theorem: D^2 = G^2 + W^2
- Half-turn Landing: Involves a 180-degree turn. The landing length (L) needs to be at least twice the sum of the tread depth (G) and the step width (W): L >= 2 * (G + W)
4. Stringer Length (for straight runs):
- Stringer Length: The length of the inclined board supporting the steps and risers, calculated as: Stringer Length = sqrt(H^2 + G^2)
H = Total Rise
N = Number of Steps
R = Step Rise
G = Tread Depth
W = Landing Width
L = Landing Length
D = Diagonal Length of the Landing
General Terms Table
To assist further, here’s a table summarizing key terms and general guidelines that are often searched by individuals looking to design stairs without diving into the calculations each time:
| Term | Description | General Guideline |
|---|---|---|
| Total Rise (H) | Vertical distance from start to end floor | Measure accurately to ensure proper step calculation |
| Step Rise (R) | Height of each step | 6″ to 7″ for comfort and code compliance |
| Tread Depth (G) | Horizontal length from the front of one tread to the next | 10″ to 11″ as per most building codes |
| Landing Width (W) | Width of the landing at the turn | At least equal to the tread depth |
| Landing Length (L) | Length of the landing, especially for turns | Depends on the type of turn, adjust accordingly |
| Stringer Length | Length of the inclined board supporting treads and risers | Calculated with sqrt(H^2 + G^2) |
Example of Stair Calculator With Landing Turn
Consider a staircase with a total rise of 120 inches aiming for a step rise of 7 inches:
- Calculate the number of steps: N = 120 / 7 = 17.14, rounded to 17 steps.
- Calculate the step rise: R = 120 / 17 approximately equals 7.06 inches.
- With a tread depth (G) of 11 inches and a landing width (W) equal to the tread depth, the landing dimensions for a quarter-turn would be determined using the Pythagorean theorem.
Most Common FAQs
The step rise should be comfortable for the user, typically between 6 inches and 7 inches. The user’s height and the available space should be considered.
Building codes usually specify a minimum tread depth of 10 inches to 11 inches, ensuring adequate foot space for safety and comfort.
The landing width should at least match the tread depth to maintain step size consistency. However, larger landings can improve comfort and safety.