Free Calculator
Roof Area Calculator
Estimate your roof area for replacement, repair, or solar planning. Calculate roofing squares and material quantities instantly.
Steeper roofs have more surface area
How to Calculate Your Roof Area
1
Choose Method
Calculate from house footprint (easier) or actual roof dimensions (more accurate).
2
Enter Dimensions
Input your building or roof measurements, pitch, and waste factor.
3
Get Results
See your total roof area, roofing squares, and material estimates instantly.
Understanding Roof Measurements
- Roofing Square: A standard unit of measurement equal to 100 square feet (about 9.29 m²).
- Roof Pitch: The steepness of your roof, expressed as rise over run (e.g., 6/12 means 6 inches of rise per 12 inches of run).
- Waste Factor: Extra material needed for cuts, overlaps, and waste. 15% is standard for most roofs.