Turn your roof footprint and pitch into roofing squares and shingle bundles for an accurate material order.
The roof surface is bigger than the footprint because of slope. We multiply the footprint by a pitch factor, add waste, and convert to squares and bundles.
Three bundles of standard architectural shingles cover one square (100 sq ft). Hips and valleys waste more material, so use 15% there. Order underlayment, starter, ridge cap and drip edge separately.
A square is 100 square feet of roof surface — the unit roofers use to price and order shingles. Most standard architectural shingles come three bundles to the square.
A sloped roof has more surface than the flat ground beneath it. A 6/12 pitch adds about 12% area, a 12/12 pitch about 41%. The multiplier converts your footprint into the real surface you have to cover.
Three bundles per square for typical architectural shingles. Heavier designer shingles can run four or five bundles per square, so check the wrapper for the exact coverage.
No. The estimate covers field shingles only. Budget separately for underlayment, starter strip, ridge cap, drip edge, flashing and nails — and always confirm before a full tear-off.
The Home Renovation Project Manager rolls every calculator into one budget — room by room, with a shopping list, contractor quote comparison and a live over-budget warning.