Roofing calculators
Roof pitch, roofing squares, shingles, metal roofing and ventilation calculators.
- Attic Ventilation CalculatorWork out the net free vent area an attic needs from its length and width, then split it evenly between low intake and high exhaust vents.
- Gutter Fall CalculatorWork out how far a gutter run drops from its high end to the downspout, and how much it drops per foot, so water runs toward the outlet.
- Metal Roofing CalculatorWork out the metal roofing panels, their cut length, the screws and the ridge, eave and rake trim for a gable or shed roof, from makers' installation guides.
- Rafter CalculatorWork out rafter length, run and ridge height for a gable roof from the building width, the pitch and the overhang before you cut lumber.
- Roof Pitch CalculatorWork out a roof's pitch from its rise and run, with the angle in degrees, the slope in percent and the slope multiplier for the roof surface.
- Roof Square CalculatorWork out the roof surface and roofing squares from a roof's footprint and pitch, with extra for waste, so you know how much shingle to order.
- Roofing CalculatorEstimate roofing squares, roof surface area and bundles of shingles from a roof's footprint and pitch, with extra for waste.
- Shingle CalculatorWork out how many bundles of shingles to buy from a roof's footprint, pitch and extra for waste, with the roofing squares and roof surface.