Roof Pitch Calculator

Calculate roof pitch, slope angle and rise/run ratio. Get instant results with visual diagrams and detailed step-by-step solutions.

Calculate Roof Pitch

How to Calculate Roof Pitch

Roof pitch is a critical measurement that expresses the steepness of a roof by comparing its vertical rise to its horizontal run. Understanding roof pitch is essential for proper roof design, material calculations, and installation. This comprehensive guide explains how to calculate and interpret roof pitch measurements.

Roof Pitch Calculation Formulas

The key formulas for calculating roof pitch measurements are:

\[ \text{Pitch Ratio} = \frac{\text{Rise}}{\text{Run}} \]

\[ \text{Pitch Angle} = \tan^{-1}(\text{Pitch Ratio}) \]

\[ \text{Pitch Percent} = \text{Pitch Ratio} \times 100\% \]

Where:

  • Rise = Vertical height of roof (inches)
  • Run = Horizontal distance of roof (inches)
  • Pitch Ratio = Rise per 12 inches of run (expressed as x:12)
  • Pitch Angle = Angle of roof slope in degrees
  • Pitch Percent = Slope expressed as percentage

Calculation Steps

  1. Measure the vertical rise of the roof
  2. Measure the horizontal run of the roof
  3. Calculate the pitch ratio (rise:run)
  4. Convert ratio to angle using inverse tangent
  5. Calculate slope percentage

Example Calculation

Problem:

Calculate the roof pitch measurements for:

  • Rise = 6 inches
  • Run = 12 inches

Solution:

  1. Calculate pitch ratio:
    \[ \text{Pitch Ratio} = \frac{6 \text{ inches}}{12 \text{ inches}} = 0.5 \text{ (6:12)} \]
  2. Calculate pitch angle:
    \[ \text{Pitch Angle} = \tan^{-1}(0.5) = 26.57° \]
  3. Calculate pitch percent:
    \[ \text{Pitch Percent} = 0.5 \times 100\% = 50\% \]

Roof Pitch Diagram

Rise Run Pitch Angle

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