How the estimator works
Roof surface area equals the footprint area (including overhangs) multiplied by a pitch factor: the square root of 1 + (rise ÷ 12)². A 6/12 roof has a factor of about 1.118; an 8/12 roof about 1.202; a 12/12 roof about 1.414. One square is 100 square feet of roof surface.
Waste and accessories
Hips, valleys and dormers waste material. Carriers commonly allow 10% to 15% depending on complexity, while cut-up roofs may need more. Starter, ridge cap, drip edge and underlayment are usually separate line items; check that each appears in your estimate.
Steep and high charges
Estimating software typically adds labor for roofs at 7/12 and steeper and for two-story eaves. Many newer homes around Charlotte and the Triangle have 8/12 to 12/12 main roofs, so confirm those charges are included. Results are rough and illustrative; a measured report or inspection is more precise.
Questions about this tool
Why doesn’t my result match the carrier’s report exactly?
Footprint estimates can’t capture every hip, valley and dormer. Differences of a few percent are normal; larger gaps are worth questioning.
How do I find my pitch?
Check the roof report in your estimate, a contractor’s measurement, or use a pitch gauge app on a gable end from a safe spot. Don’t climb a damaged roof.
Do I include the garage and porch?
Yes, if their roofs are part of the claim. Enter them separately and add the results, since pitches often differ.