Roofing Calculator
Sloped roof surface from rectangular footprint and pitch (degrees, %, or x:12); optional cost from price per unit roof area.
Uses planar footprint length × width for base area, then roof surface ≈ base ÷ cos(pitch) for a simple gable/shed-style slope model—hips, valleys, and dormers need field measurement.
Pitch links degrees, percent rise/run, and x:12; add waste and accessory allowances outside this estimate.
House dimensions
Footprint length and width on the ground; base area is length × width. Gable or shed roof models use slope area ≈ base ÷ cos(pitch).
Roof pitch
Enter any one of the three; the others update. Pitch in degrees, percent rise over run × 100, or rise per 12 in run (x:12). Max 85° for this estimator.
Roof cost
Rough budget: multiply roof surface area by your all-in price per unit area (materials, labor, accessory waste as quoted).
Per unit of roof area — uses the same area unit as “Roof area” and “House base area” above.