Home Improvement
Roof Tile Calculator
Enter roof area (or length×width×pitch factor), tile coverage and waste to see tiles and packs.
How many roof tiles do I need?
Roof tile counts follow slope area and each tile’s coverage. Enter a known roof area, or build plan length × width × a pitch factor that converts plan footprint into slope area (steeper roofs need factors above 1). Divide area by coverage per tile, add waste for cuts and breakages, then round up to pack sizes. Manufacturer coverage already assumes a stated lap — use the figure on the pack, not a guess. Cross-check pitch geometry with the roof pitch calculator and related covering maths with tile calculator for walls or floors.
Worked example
8 × 6 m plan × 1.15 pitch factor ≈ 55.2 m². At 0.03 m²/tile → 1,840 tiles; +10% ≈ 2,024; packs of 36 → 57 packs.
Limits and assumptions
Ignores hips, valleys and dormers as separate extras — add waste or measure those planes. Not a fixing or underlay specification.
Frequently asked questions
What is a pitch factor?
A multiplier that turns flat plan area into the larger sloping roof surface. Steeper roofs use higher factors; 1.0 means flat.
Where do I find coverage per tile?
On the manufacturer data sheet — it already folds in the recommended lap.
Is 10% waste enough?
Simple rectangles often sit near 5–10%; complex roofs with many cuts commonly need more.
Should I order underlay here?
No — this counts tiles only. Underlay and battens are separate take-offs.