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Roof Area Calculator

Estimate your roof area in m² and roofing squares — useful for replacement quotes, material ordering, or solar panel planning.

Roof Area Calculator

Estimate your roof area in m² and roofing squares.

Steeper roofs have more surface area

How the Roof Area Calculator Works

This calculator uses your building's footprint or roof dimensions, combined with the roof pitch and a waste factor, to estimate the total area of roofing material you'll need.

  • Roof Pitch multiplies the flat footprint to account for the slope — a steeper roof has more surface area.
  • Waste Factor adds extra for cuts, overlaps, and unusable offcuts — typically 10–20% depending on complexity.
  • Roofing Squares is the industry unit (1 square ≈ 9.29 m²) used to measure material quantities.

Also try our Roof Condition Assessment to find out if you need repair or replacement.

Take the Assessment →