Roofing Calculator
Enter building length/width (ft) and roof pitch to estimate total gable roof area in square feet and square meters.
Input Data
Results
1,341.6
124.6
At a glance:Gable roof: halfW = width ÷ 2; rise = (pitch ÷ 12) × halfW; slope = √(halfW² + rise²); roof area = 2 × length × slope.
Formula
halfW = width ÷ 2; rise = (pitch ÷ 12) × halfW.
slope = √(halfW² + rise²).
area = 2 × length × slope; sqm = area × 0.092903.
How to Use
- Enter building length, width (ft) and pitch x/12.
- Get total gable roof area instantly.
FAQ
What is pitch x/12?
It means rising x inches per 12 horizontal inches, the common North American roof-pitch notation (e.g. 6/12 is moderate).
Should I add waste?
Add about 10% for overlap and waste when purchasing; this calculator reports net area.
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References
Content reviewed by the Calculatorism editorial team. Results are for reference only; please refer to the relevant authorities for the official figures.