[header] How to estimate roofing materials [title] Find the square footage of the roof. [step] Measure the length and width of each portion of the roof, multiply length by width for each plane, and then add the planes together for the total square footage. [title] Determine the total number of squares. 
[step] Divide the total footage by 100 to determine the number of " squares " in the roof. [title] Determine the bundles of shingles needed to cover the roof.