Roof Calculator
Calculate roof area and material quantities.
Simple gable estimate from building footprint and roof pitch. Complex hips/valleys need a surveyor’s measure.
Tiles, shingles, or sheets — check the pack
Roof surface area
92.4 m²
Pitch factor ×1.155
Footprint
80 m²
Packs (exact)
92.4
Packs to buy
102
In-depth explanation
Estimate gable roof surface area from building footprint and pitch angle, then convert to packs using coverage and wastage. Everything runs locally in your browser — your inputs are not uploaded to produce the result.
Steeper roofs have more surface area. Area ≈ footprint ÷ cos(pitch angle). It’s a simple gable approximation. Hips, valleys, and dormers need a more detailed take-off.
How much roof area one pack of tiles/shingles covers — check the product label. Tweak the inputs above to compare options, then copy or note the result you need.
Pitch increases surface area: area ≈ plan area ÷ cos(pitch). A gable on a rectangle is the model. Hips, valleys, dormers, and chimneys need a proper roofing take-off.
Pack coverage for tiles or shingles is on the product. Wastage is higher on complex roofs. This is not a structural load calculation and not a substitute for a roofer’s measure.
Frequently asked questions
How does pitch affect area?
Steeper roofs have more surface area. Area ≈ footprint ÷ cos(pitch angle).
Does this work for hip roofs?
It’s a simple gable approximation. Hips, valleys, and dormers need a more detailed take-off.
What is pack coverage?
How much roof area one pack of tiles/shingles covers — check the product label.
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