How the roofing cost estimate is calculated
This calculator is a planning tool, not a contractor quote. It uses national U.S. component ranges and does not claim to know a ZIP-code-specific contractor bid.
Formula
For supported materials, the calculator separates material, installation labor, and optional tear-off:
material cost = roof area × (1 + waste %) × material rate
labor cost = roof area × labor rate
tear-off cost = roof area × tear-off rate (only when selected)
total = material + labor + tear-off
The “Typical” number is the midpoint of the calculated Low and High planning totals. It is not claimed to be a market quote.
Published rates used by Easy Mode
| Material | Material | Labor | Tear-off | Waste default |
|---|---|---|---|---|
| 3-tab asphalt | $0.80–$1.30/sq ft | $2.00–$3.00/sq ft | $1–$3/sq ft | 10% |
| Architectural asphalt | $1.00–$2.50/sq ft | $3.00–$3.50/sq ft | $1–$3/sq ft | 10% |
| Metal (broad) | $1.00–$8.00/sq ft | $4.00–$8.00/sq ft | $1–$3/sq ft | 0% |
The national estimate does not add separate adjustments for location, roof pitch, story height, permits, decking repairs, gutters, skylights, or hidden structural damage. Local contractor quotes are the best source for project-specific factors.
Sources
Material-specific shingle labor, metal labor, and tear-off ranges.
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GAF states that one roofing square equals 100 sq ft, most standard asphalt shingles use three bundles per square, and a 10–15% trim/waste allowance is commonly added.
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National roofer mean hourly wage $27.95; median hourly wage $26.65. The calculator does not convert this wage directly into a contractor billing rate.
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What the estimate does not know
- Your contractor’s overhead, profit, insurance, crew productivity, or scheduling constraints.
- Local permit fees, code upgrades, ice/water shield requirements, or disposal rules.
- Decking damage hidden under the existing roof.
- Exact valley, dormer, chimney, skylight, flashing, and access complexity.
- A state-by-state price multiplier. The calculator uses national ranges rather than claiming a local adjustment without a documented source.
For a purchase decision, compare multiple written contractor bids and confirm exactly what each bid includes.