Roof Covering Calculator
Pick the roofing material (clay tile, shingle, metal sheet) and the roof area — see a rough area with 10% waste allowance and the required material quantity based on common coverage rates.
We typically respond within 24 hours.
Let's determine the right quantity and details together based on your roof's real geometry and chosen covering materialThis is a rough illustration using a common reference coverage rate for the selected material; actual material size, coverage area, and waste allowance vary by manufacturer, roof geometry (number of ridges/valleys), and chosen profile.
How is the required roofing material quantity calculated?
Roofing material quantity is calculated by dividing the roof surface area (m²) by the unit coverage area of the selected material. A waste allowance of around 10% is typically added to the calculated area for ridge, valley, eave cuts, and overlap margins.
The tool above uses a common unit coverage rate for your selected covering material to show the roof area with a waste allowance, plus the required material quantity.
Common coverage rates by material type
On clay tile (Marseille type) roofs, 1 m² is typically covered by about 13 tiles; bitumen shingle bundles typically cover about 3 m² per bundle; trapezoidal/metal sheets provide about 2 m² of coverage per standard sheet.
This tool uses a common reference rate for each material — actual material size and coverage area vary by manufacturer and chosen profile.
Why the waste allowance varies with roof geometry
A 10% waste allowance is usually enough for a simple, mono-pitch or symmetrical gable roof; hip roofs, multiple ridges/valleys, or complex roof geometry can increase this rate. This tool uses 10% assuming a standard gable roof — the exact quantity should be calculated from the roof plan.
Let's determine the right quantity and details together based on your roof's real geometry and chosen covering material.
Contact usFrequently Asked Questions
How is the required roofing material quantity calculated?
Simple formula: Quantity = (Roof Area (m²) × 1.10) ÷ Unit Coverage Area. For example, an 80 m² roof covered with clay tiles covering about 0.077 m² per tile needs (80 × 1.10) ÷ 0.077 ≈ 1,143 tiles.
Why is the roof waste allowance around 10%?
Ridge, valley, eave cuts, and tile/shingle overlap margins mean real consumption exceeds the calculated net area. 10% is usually enough for simple roof geometries; this rate can increase for complex roofs.
What is the difference between clay tile, shingle, and metal sheet?
Clay tile (Marseille/Alaturka type) is a traditional and durable material; bitumen shingle is lighter and adapts easily to complex roof geometries; trapezoidal/metal sheet offers fast installation and lower cost. The choice depends on budget, roof pitch, and aesthetic preference.
Is this tool the same as the Roof Pitch Calculator?
No, it performs a different calculation. The Roof Pitch Calculator computes the minimum pitch percentage and ridge height; this tool calculates the required covering material quantity (pieces/bundles) based on the selected roof area. The two can be used together.