Quick estimate mode — for underlay, battens, ridge tiles and cost breakdown:
Full calculator →
Quick Roof Material Calculator
Enter your roof area and material type to get the quantity to order — including waste.
Result
Quantity to buy
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Order from the same batch where possible — colour and texture can vary between production runs.
Need underlay, battens and ridge tiles too?
Full calculator covers all roofing materials plus cost estimate.
How to calculate roofing materials
The formula
Quantity = ⌈(Roof area × (1 + waste %)) × tiles per m²⌉
For asphalt shingles, one "square" = 100 sq ft (≈ 9.29 m²), typically covered by 3 bundles.
Typical coverage rates
Concrete tiles: ~10 per m². Clay tiles: ~16 per m². Natural slate: ~20 per m². Asphalt shingles: 3 bundles per square (100 sq ft). Metal panels: ordered by m².
Why add waste?
Ridge lines, hip edges, valleys and dormers all require cut pieces. A standard gable roof needs ~10% waste. Add 15–20% for hip roofs or complex shapes with multiple penetrations.
Pro tip: Keep 5–10 spare tiles after the job. Matching replacements years later is difficult — batches vary in colour even from the same manufacturer.