Roof Pitch Calculator

Calculate roof pitch, angle, and related measurements for your roofing projects. The roof pitch is the slope of a roof, representing the vertical rise divided by the horizontal run or span.

Roof Pitch Calculator

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Understanding Roof Pitch

RunRiseRoof SlopePitch Angle

Roof pitch is typically expressed as a ratio of vertical rise to horizontal run. In the US, it's often stated as "X:12" (e.g., "6:12"), meaning a rise of X inches per 12 inches of horizontal run.

  • Low Pitch: 2:12 to 4:12 (9.5° to 18.4°)
  • Medium Pitch: 4:12 to 9:12 (18.4° to 36.9°)
  • Steep Pitch: 9:12 and up (36.9°+)

Common Pitch Applications

  • Flat Roofs: 1:12 or less, used in commercial buildings
  • Low Slope: 2:12 to 4:12, often for ranch style homes
  • Conventional: 4:12 to 9:12, common in residential
  • Steep Slope: 9:12 or greater, Tudor, Victorian styles

More About Roof Pitch

Why Roof Pitch Matters

Roof pitch affects many aspects of construction, including:

  • Water drainage and snow load capacity
  • Roofing material options and installation requirements
  • Attic space and potential for living area
  • Overall home style and aesthetics
  • Installation costs and complexity

Calculating Materials

When planning a roofing project, knowing the pitch helps determine:

  • The actual roof area (which is larger than the building footprint)
  • Appropriate underlayment and flashing requirements
  • Quantity of roofing materials needed (shingles, tiles, etc.)
  • Labor costs, as steeper roofs are more difficult to work on