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Stair Calculator (Rise, Tread, Steps & Angle)

Architecture and carpentry tool. Designs safe ergonomic stairs complying with International Building Code (IBC) and Blondel's Rule ($2h + d \approx 63\text{ cm}$).

Input Parameters

Instant Calculation Result

Estimated Output
Active in Real-Time

Adjust values on the left to calculate live results.

Formula: Step Count N = round(TotalRise / 7.5). Actual Riser = TotalRise / N. Incline Angle θ = atan(Riser / Tread) * (180/π). Blondel's Rule: 2*Riser + Tread ≈ 25 inches (63 cm).

In-Depth Guide & Mathematical Methodology

🪜 IBC Building Code Stair Standards

Maximum Riser Height: 7.75 inches (19.7 cm) max per step.

Minimum Tread Depth: 10.0 inches (25.4 cm) min per step.

Blondel's Ergonomic Rule: 2 × Riser + 1 × Tread ≈ 24 to 25 inches (62 to 64 cm).

Frequently Asked Questions (FAQ)

What is the Stair Calculator (Rise, Tread, Steps & Angle) and how does it work?

Architecture and carpentry tool. Designs safe ergonomic stairs complying with International Building Code (IBC) and Blondel's Rule ($2h + d \approx 63\text{ cm}$).

How do I use this Stair Calculator (Rise, Tread, Steps & Angle)?

Enter Total Stair Rise (vertical height) in inches. Enter Desired Tread Depth (horizontal step) (e.g. 10 inches). View Number of Steps required, Exact Riser Height, and Incline Angle.

What mathematical formula is used in this calculation?

Step Count N = round(TotalRise / 7.5). Actual Riser = TotalRise / N. Incline Angle θ = atan(Riser / Tread) * (180/π). Blondel's Rule: 2*Riser + Tread ≈ 25 inches (63 cm).

Is the Stair Calculator (Rise, Tread, Steps & Angle) on FindCalculator free to use?

Yes, all 330+ interactive tools on FindCalculator.online are 100% free, run directly in your browser without registration, and do not store your private calculation data.

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