Roof Area & Pitch Calculator
Calculate true roof surface area for Gable, Hip, and Shed roofs with pitch multipliers, shingle squares, and metal sheets.
Building Footprint & Slope
Roof Pitch Explained
• Flat / Low (1:12 to 3:12): Requires membrane/torch-on waterproof roofing.
• Standard (4:12 to 8:12): Ideal for asphalt architectural shingles and metal roofing sheets.
• Steep (9:12 to 12:12+): Sheds heavy snow and rain rapidly; requires safety harnesses.
How to Use Roof Area & Pitch Calculator
- Select your roof structure style: Gable Roof, Hip Roof, Shed / Monoslope, or Flat Roof.
- Enter the base building length and width (ground footprint) in feet or meters.
- Add the eaves overhang depth (e.g. 1 ft / 12 inches).
- Select the roof pitch/slope ratio (e.g. 4:12, 6:12, 8:12, or custom degrees).
- View the total true roof surface area, roofing squares, shingle bundle packs, underlayment rolls, and ridge cap length.
Key Features & Privacy Guarantee
- 4 Architectural Roof Types: Gable (dual slope), Hip (quad slope), Shed (monoslope), and Low-slope Flat roofs.
- True Slope Pitch Multiplier: Exact trigonometric pitch factor calculation (Multiplier = √(1 + (Rise/Run)²)).
- Roofing Squares & Bundles: Computes standard 100 sq ft 'Roofing Squares' and 33.3 sq ft asphalt shingle bundles.
- Alternative Material Support: Standing seam metal roof panels, clay/concrete roof tiles, and synthetic underlayment rolls.
- Ridge Cap Length: Calculates linear feet of ridge capping needed along roof peaks.
Frequently Asked Questions
What is a 'Square' in roofing terms?
In roofing terminology, one 'Square' is a unit of measurement equal to exactly 100 square feet (9.29 m²) of roof surface area.
How many bundles of shingles make 1 square of roof?
Standard 3-tab and architectural asphalt shingles typically come packed as 3 bundles per square (each bundle covers ~33.3 sq ft).
What does a 6:12 roof pitch mean?
A 6:12 pitch means the roof rises 6 inches vertically for every 12 inches (1 foot) of horizontal run. This corresponds to a roof angle of approximately 26.57 degrees with a slope multiplier of 1.118.
Why do eaves overhangs affect roof square footage?
Overhangs extend beyond the exterior walls of the house (typically 12 to 24 inches on all sides) to channel rainwater away from foundations, increasing the total roof area compared to the building's ground floor footprint.