Roof Area & Pitch Calculator — m, degrees, m²
How to use this calculator
Calculate actual roof area from building footprint and pitch in metric. Three input modes: footprint + angle in degrees, rise + run measurements in meters, or direct angle entry. Choose roof shape (gable, hip, shed) and add extra sections for complex roofs. Includes SVG pitch profile diagram.
Pitch factor (PF) = 1 / cos(angle). Multiply footprint area by PF to get true roof surface area.
Multi-section — Add additional roof sections with independent pitch for dormers or extensions.
Saved Calculations
| Time | Shape | Angle | PF | Footprint m² | Roof Area m² | Rafter m |
|---|
How to Calculate Roof Area from Pitch (Metric)
This calculator converts between pitch angle (degrees) and rise:run ratio, and calculates actual roof surface area from building footprint. Supports gable, hip, and shed shapes with multi-section capability for complex roofs.
Formulas
Pitch factor = 1 / cos(angle°). Rafter length = run / cos(angle°). Rise = run × tan(angle°). Roof area = footprint area × pitch factor. The rise:run equivalent shows the pitch in the common X:12 format.
Common Angles
10° (low slope) · 15° (minimum for tiles) · 20° (standard) · 30° (steep) · 45° (very steep, 12:12 equivalent).
