Home Improvement
Drywall Calculator
Estimate drywall sheets from known area or four walls plus the ceiling of a rectangular room.
Roofing Shingle Calculator
Estimate roofing squares, waste-adjusted area, and product-specific bundles.
Use measured roof surface area without assuming every bundle has identical coverage.
Enter your details
Roof area and shingle coverage
Roof squares before wasteArea including wasteRounded-up bundle estimate
Your estimate will appear here
Complete the fields and calculate to see a detailed result.
Material quantity only
A roofing square is area, not a package count. Enter manufacturer bundle coverage.
Formula and methodology
Roof squares = area ÷ 100. Adjusted area is area × (1 + waste ÷ 100). Bundles are adjusted area ÷ coverage, rounded up.
Worked example
A 2,000 sq ft roof is 20 squares. With 12%, area is 2,240 sq ft. At 33.3 sq ft per bundle, 67.27 rounds to 68.
Assumptions and limitations
Valleys, hips, ridges, starter, caps, flashing, underlayment, packaging, and cuts need separate review. No slope-safety, structural, load, or code advice is provided.
Frequently asked questions
What is one square?
One roofing square is 100 sq ft.
Why enter bundle coverage?
Products differ.
Can I use footprint area?
Only after converting it to roof surface area.
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