How to use this calculator
This estimate adjusts the horizontal footprint using a roof-pitch factor. Complex roofs require direct measurement or a professional estimate.
Formula
Roof area ≈ Building length × width × pitch factor
Example
A 40 ft by 30 ft footprint with a 6:12 pitch uses a factor of about 1.118, giving roughly 1,342 ft².
Frequently asked questions
Does this include waste?
No. Material orders often include a separate waste allowance based on roof complexity.