Roofing & Exterior Calculators

Exterior estimates share one complication that interior work doesn’t: geometry you can’t easily tape-measure. A roof’s real area is its footprint stretched by the pitch multiplier — a 6/12 roof has about 12% more surface than the house’s outline suggests. Gable walls are triangles pretending to be rectangles. A fence line’s post count depends on rounding to whole sections, not on dividing feet by spacing.

Each calculator here does that geometry for you. The shingle tool applies the exact pitch multiplier (√(1 + (pitch/12)²)) and converts to squares and 3-bundles-per-square. The siding tool takes walls and gables piece by piece, deducts openings, and outputs squares plus vinyl piece counts. The fence tool turns a run of feet into posts, rails, pickets and concrete bags.

Waste matters more outdoors than in: staggered siding ends, hip and valley cuts, and picket culls all eat material. The defaults here (10% for roofs and siding) suit straightforward layouts — bump them for cut-up roofs and curved fence lines, and the tools will show you the with-waste number next to the raw one so nothing is hidden.