Roof plan

Define area and asphalt scope

6 inputs

Area you have

Use known roof surface when a takeoff already accounts for slopes and roof planes.

Building footprint / horizontal roof plan area

Do not enter total living area across multiple stories.

Roof pitch

Rise in inches for every 12 inches of horizontal run. Use a professional takeoff for mixed pitches.

Material waste / trim allowance

GAF describes 10%–15% as a typical planning allowance; roof layout can require more.

Asphalt shingle type

Only material types with compatible source rows and standard-asphalt bundle guidance are modeled.

Include old-roof removalAdds HomeGuide's published tear-off component; deck repairs remain excluded.

No regional, story, access, complexity, or steep-pitch cost multiplier is applied.

Area first, scope second

How the roofing calculator works

Footprint mode applies the selected pitch through a geometric slope factor. Known-roof-area mode does not apply pitch again. Both paths convert measured surface into roofing squares, then apply waste only to asphalt material quantity.

The cost range adds HomeGuide's registered material-only asphalt row, replacement-labor row, and optional old-roof-removal row. GAF's standard three-bundle rule and 10%–15% waste guidance drive quantity, not price.

Read the roof replacement cost and scope guide

Carry the assumptions into quote comparison

Ask each bidder to show roof surface, waste, order quantity, old layers, removal and disposal, deck-repair unit prices, underlayment, flashing, ventilation, permits, warranties, and exclusions.

Review how Ramefor separates source rows and calculator rules