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Roofing Calculator

Calculate roofing materials, costs, and labor for residential and commercial projects

Calculate Roofing Materials

Roof Dimensions

Cost Estimates (per square - 100 sq ft)

How to Use the Roofing Calculator

Getting Started

  • Select Roof Type: Choose from gable, hip, shed, or gambrel designs
  • Enter Dimensions: Provide building footprint length and width
  • Set Roof Pitch: Input rise over 12" run (e.g., 4/12, 6/12)
  • Choose Materials: Select from asphalt, metal, tile, or slate

Roof Types

  • Gable: Simple triangular roof with two slopes
  • Hip: Four-sided roof sloping from all sides
  • Shed: Single sloped roof
  • Gambrel: Barn-style roof with two slopes per side

Understanding Measurements

  • Length/Width: Building footprint dimensions
  • Pitch: Rise over 12" run (e.g., 4/12, 6/12, 8/12)
  • Ridge: Peak length where roof sections meet
  • Eave: Lower edge perimeter for gutters

Professional Tips

  • Safety First: Professional installation recommended for steep roofs
  • Weather Planning: Install during dry season for best results
  • Permit Requirements: Check local building codes and permits
  • Ventilation: Ensure proper attic ventilation with new roof

Frequently Asked Questions

How many squares do I need for a 1,200 sq ft house?

For a simple gable roof on a 1,200 sq ft house, you'll typically need 13-15 squares depending on roof pitch and overhang.

What's the difference between roof pitch and slope?

Pitch is expressed as rise over 12" (4/12), while slope is rise over run as a ratio (1:3). Higher pitch means steeper roof and more materials needed.

How long do different roofing materials last?

Asphalt shingles: 20-30 years, Metal: 40-70 years, Tile: 50+ years, Slate: 100+ years. Consider longevity vs. upfront costs.

Should I remove old shingles or roof over them?

Removal is recommended for best results, though some codes allow one layer over. Removal allows inspection of decking and better installation.

What affects roofing labor costs?

Pitch steepness, roof height, access difficulty, material type, removal requirements, and local labor rates all impact installation costs.

How much waste should I add to my material order?

Standard waste is 10% for simple roofs, 15% for complex roofs with multiple angles, dormers, or valleys.

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