Roof Area Calculator

Calculate the roof surface area for materials estimation — tiles, felt or metal.

✓ Free✓ Instant results✓ Mobile friendly✓ No sign-up

Building Length (m)

Building Width (m)

Roof Pitch (degrees)

Roof Type

Roof Area (m²)

Footprint (m²)

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How Roof Area is Calculated

Roof area = footprint area ÷ cos(pitch angle). Pitch (rise/run) determines how much larger the roof area is compared to the floor area.

What is a standard roof pitch in the UK?+

A 35–40° pitch is most common for UK houses. Flat roofs have a pitch of 1–5°. Steep Victorian roofs can be 45°+.

How many roof tiles do I need?+

Divide the roof area by the coverage per tile. Standard plain tiles: ~60 tiles/m². Concrete interlocking tiles: ~10 tiles/m².