From footprint to squares
A roofing square is 100 square feet of roof surface. The calculator adds your eave overhang to the footprint, multiplies by the pitch factor (the slope’s true length per foot of run) and divides by 100. Waste covers cutting at hips, valleys and dormers.
New York details to check in the estimate
- Multiple layers. Many older homes from Queens to Buffalo carry two layers of shingles. Each layer should be removed and priced.
- Steep and high charges. Pitches of 7/12 and above, and roofs above two stories, typically add labor.
- Ice and water shield. Code-required eave protection in snow country is an easy line to miss.
- Drip edge, starter and ridge. Small lines that add up.
Worth knowingFootprint math is an approximation. Aerial measurement reports or a field measurement are what a panel will rely on. Use this to spot a large gap, then verify.
Hail or wind on the roof? See roof & hail damage appraisal and snow load & ice dam appraisal.
Questions about this calculator
Why is my result different from the carrier’s squares?
Differences usually come from pitch, overhangs, waste or missed sections such as porch roofs and dormers. Compare section by section.
What waste factor should I use?
Simple gables often run around 10%; hips and cut-up roofs run higher. Your estimate should explain the waste it applied.
Does the calculator handle flat roofs?
Choose 2/12 for a near-flat roof. Membrane roofs are priced differently from shingles, so treat the cost line with care.