Roofing Calculator
Calculate sloped roof area and covering sheets from building dimensions, pitch and overhang.
🛡 Privacy-first⚡ Fast🔓 No signup📱 Mobile friendly
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⚠️ Results are estimates for takeoff and planning. Do not use them as a substitute for structural design, specifications or local building codes; consult a qualified professional when required.
🔎 Use Roofing Calculator with a clear, professional workflow
Calculate actual gable or shed roof area and covering-sheet quantity from building length, width, pitch angle and overhang.
The tool is designed for a clearer mobile and desktop workflow, with organized inputs and results plus copy or print actions where appropriate.
- Clear quantity results for takeoff and planning.
- Practical inputs with cost details where supported.
- Estimates do not replace approved engineering design.
Worked examples and practical tips
Roof surface area is larger than the horizontal footprint on a pitched roof; a slope correction is required.
Correcting projected roof area for slope
A horizontal roof area of 100 m² at a 6:12 pitch needs a slope factor of about 1.118, giving about 111.8 m² of surface before waste.
Slope factor = √(1+(rise/run)²), using consistent units.
💡 Calculation notes
Estimate roof surface area from dimensions and slope, then add a waste allowance for material planning. Check the output before ordering.
- Actual orders depend on roof geometry, openings, overlaps and product coverage.
- Do not use a rough estimate as a structural design or construction safety specification.
ℹ️ How to use
- Enter your data or choose the required file.
- Adjust the available options.
- Run the tool and review the result.
- Copy or download the result when needed.
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