Roof Area Calculator
Enter the plan (footprint) length and width of the roof and the pitch in degrees. We convert that to approximate roof surface area, with optional waste for hips and valleys.
Results
- Plan area
- —
- Pitch factor
- —
- Roof surface
- —
- Order allowance
- —
Surface area uses plan × 1/cos(pitch). Always confirm with a site measure before ordering materials.
Planning estimate only. Skylights, verandahs, multi-level planes and unusual geometry need professional measure. Book a free inspection across Brisbane to the Sunshine Coast.
Why roof area matters
Sheet counts, insulation, screws and ballpark quotes all start from roof surface m², not just the house floor plan. A 22.5° pitch increases surface area by about 8% versus flat; steeper roofs rise further.
Next: use the sheet quantity calculator or cost estimator.
Planning a roof in Brisbane or on the Coast?
Use the calculators for ballparks, then get a site measure for materials that fit your home.
Call 0411 510 699