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.
Assuming a symmetrical gable roof: footprint ÷ cosine of the pitch angle. Eave overhangs, chimneys and roof-window openings are not included.
The plan is drawn to scale as a square with the roof area you entered; the dashed square shows the area a single roofing unit covers, at the same scale.
| Clay Tile (Marseille Type)Selected | |
| Shingle (Bitumen)Selected | |
| Metal / Trapezoidal SheetSelected |
Optional. Enter the unit price (piece/bundle/sheet) you see at the store and we will total it up.
Enter the unit price
The total is simply your price multiplied by the required quantity; labour and ancillary materials (sheathing, membrane, nails/screws) are not included.
We usually reply the same day.
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 many roof tiles per m², and how many in total?
The tile used in this tool covers about 0.077 m² each, so roughly 13 pieces per m². The count varies by tile type. Concrete tiles are commonly taken as about 10 per m², Marseille and clay tiles around 15 per m². For the total: Quantity = (Roof Area (m²) × 1.10) ÷ Unit Coverage Area. For an 80 m² roof: (80 × 1.10) ÷ 0.077 ≈ 1,143 tiles. Enter your roof area in the tool above to see the count directly.
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.