Roofing Calculator
Estimate roofing from surface area, coverage, and waste allowance. Use this free roofing calculator for fast, clear results with no signup required.
Roofing Calculator guide
What it is for
Plan material quantities for roofing calculator before purchasing supplies.
How it is calculated
Packages needed = ceil(length in feet × width in feet × 1.10 / package coverage in square feet). This includes a fixed 10% waste allowance and rounds up to whole packages.
Assumptions
The surface is reasonably regular and the dimensions, coverage, and waste represent the real project.
Example
Worked example using the fields in order: 12, 10, 100. The calculated primary amount is 2 packages; the secondary value is 120. Check the units before purchasing.
Limitations
Cuts, openings, packaging, site conditions, and local codes can change the final quantity; confirm with a supplier or professional.