About this calculator
Estimate roof covering area, squares and pack count.
Complex roofs, valleys and hips need more careful take-offs.
Formula
Roof area ≈ plan area × pitch factor. Order area = roof area × (1 + waste%).
Example
A 60m² plan area at 1.12 pitch factor ≈ 67.2m² actual surface before waste.
Accuracy
NUMTX shows the assumptions next to the calculation so you can replace defaults with values that match your situation. For measurements, supplier rates, fees, interest, tax or regulated work, confirm important figures with the appropriate official or professional source.