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Roof Tile Quantity Calculator

Work out how many roof tiles you need by area.

What is the Roof Tile Quantity Calculator?

A roof tile quantity calculator works out how many tiles are needed to cover a roof, based on the roof area, the manufacturer's tiles-per-m² coverage rate (which depends on tile profile and gauge) and a waste allowance for cuts and breakages. It works by multiplying roof area by tiles-per-m² to get a base quantity, then adding a percentage on top for waste. To calculate it manually: roof area × tiles per m², then multiply by (1 + waste% ÷ 100) and round up — this covers the main roof area only, excluding ridge, hip and verge tiles, and the exact coverage rate should always be checked against your specific tile manufacturer's published figures.

How it works

Tile quantity is worked out by multiplying your total roof area by the tile coverage rate (how many tiles are needed per square metre for your specific tile profile and gauge), then adding a waste allowance for cuts, breakages and complex roof details.

UK context

Tiles-per-square-metre varies significantly by tile type — a large-format concrete interlocking tile covers more area per tile than a small traditional clay plain tile, so the coverage rate genuinely depends on your specific product, not a single universal figure.

Tips

Always use the coverage rate stated by your specific tile manufacturer rather than a generic estimate — this varies meaningfully between tile profiles.
This calculation excludes ridge, hip and verge tiles, which are typically ordered separately based on the roof's linear dimensions rather than area.
Complex roofs with lots of hips, valleys and cuts need a higher waste allowance than a simple gable roof, since more tiles need to be cut to fit.

Frequently asked questions

How many tiles do I need per square metre?

This depends entirely on your specific tile's size and profile — check the manufacturer's stated coverage rate (tiles per m²) for the exact product you're using, since it varies significantly between tile types.

Does this include ridge and hip tiles?

No — this calculates the main roof field tiles by area. Ridge, hip and verge tiles are typically calculated separately based on the roof's linear measurements.