Roofing Calculator

Use this roofing calculator to estimate the sloped area of a rectangular roof, add a waste allowance and convert the result into roofing squares and shingle bundles. It is practical for early budgeting, material takeoffs and quick comparisons before ordering.

Enter roof length, width, pitch as rise over run, waste percentage and bundle coverage. The calculator converts between square meters and square feet, shows the pitch multiplier and gives a useful baseline for gable, hip or shed roofs with a consistent pitch. For complex roofs with many valleys, dormers or cutouts, treat the result as a planning estimate and confirm the final layout on site.