4/12 Roof Pitch Calculator

Roof Pitch Angle Formula:

\[ \text{angle} = \arctan\left(\frac{\text{rise}}{\text{run}}\right) \times \left(\frac{180}{\pi}\right) \]

Roof Pitch Angle:

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1. What is Roof Pitch Angle?

The roof pitch angle is the angle of a roof's slope measured from the horizontal. A 4/12 pitch means the roof rises 4 inches vertically for every 12 inches of horizontal run.

2. How Does the Calculator Work?

The calculator uses the trigonometric formula:

\[ \text{angle} = \arctan\left(\frac{\text{rise}}{\text{run}}\right) \times \left(\frac{180}{\pi}\right) \]

Where:

\( rise \) — Vertical rise (inches)
\( run \) — Horizontal run (inches)
\( \arctan \) — Inverse tangent function
\( \frac{180}{\pi} \) — Conversion factor from radians to degrees

Explanation: The formula calculates the angle by finding the ratio of rise to run, then converting the resulting radians to degrees.

3. Importance of Roof Pitch

Details: Roof pitch affects water drainage, material selection, snow load capacity, and aesthetic appeal of a building.

4. Using the Calculator

Tips: Enter rise and run values in inches. For standard roof pitches like 4/12, the calculator will show the corresponding angle in degrees.

5. Frequently Asked Questions (FAQ)

Q1: What does a 4/12 roof pitch mean?
A: It means the roof rises 4 inches vertically for every 12 inches of horizontal run.

Q2: What angle is a 4/12 roof pitch?
A: Approximately 18.43° (as calculated by this tool).

Q3: Is 4/12 a common roof pitch?
A: Yes, it's a moderate slope that works well with most roofing materials.

Q4: What roof pitch is best for snow?
A: Steeper pitches (6/12 or more) are better for snowy areas as they help snow slide off.

Q5: Can I walk on a 4/12 pitch roof?
A: Yes, with proper safety equipment, though caution is always needed on any sloped roof.