contractor · 2026-05-01

Roofing bid cost calculator

Estimate materials + labor + dump fees for an asphalt-shingle reroof. Squares-based estimate that mirrors how real roofers price.

Total roofing bid
$11,377
Materials + labor + overhead

Inputs

Roof squares25
Material $ per square$110
Labor $ per square$175
Tear-off $ per square$60
Dumpsters needed1
Dumpster fee (each)$450
Permit fee$250
Contractor overhead + profit %22%

Supporting metrics

Materials cost$2,750
Labor cost (install + tearoff)$5,875
Dumpster + dump fees$700
Overhead + profit$2,052
All-in $ per square$455

About this calculator

Roofing bid math — squares first, then everything else

A roofer's bid is built on squares, not square feet. One square = 100 sqft of roof surface. Pitch and complexity matter, but the squares number anchors every other line item: shingles, underlayment, dump fees, labor.

The four cost buckets

  1. Materials — shingles, underlayment, ice & water shield, drip edge, vents, ridge cap. Architectural 30-year shingles run $90-130/sq, premium / impact-rated $150-220/sq.
  2. Labor — install + tear-off. Most reroofs include tearing off the old layer (code in most jurisdictions if you're already on layer two). Combined labor is $150-300/sq depending on pitch and access.
  3. Dump fees + permit — a 20-yard dumpster handles 20-25 squares of tear-off. Permit is jurisdiction-dependent, $150-500.
  4. Overhead + profit — 20-25% markup on the rest covers warranty, insurance, vehicles, and the contractor's actual profit. If a bid doesn't include this, the contractor will eat into job quality to survive.

Why bids vary 30%

Steep pitch (>8/12) adds harness time. Multiple layers of existing roof double tear-off labor. Skylight flashing, satellite mounts, and chimney crickets all add line items. The squares × rate formula gives the floor — adjust upward for complexity.

FAQ

How do I figure out my roof's squares without going up there?

Take your home's heated square footage, multiply by 1.25 for a typical 6/12 pitch, then divide by 100. A 2,000 sqft house ≈ 25 squares. For a steeper pitch, use 1.4-1.5×. Best version: have a contractor pull a satellite measurement (HOVER, EagleView, etc.) — usually free with a quote.

Should the bid include tear-off, or can I leave the old layer?

Most building codes allow a maximum of two roof layers. If you're already on layer two, code requires tear-off. Even when allowed, layering over old shingles voids many manufacturer warranties and traps moisture. Bid tear-off in.

Why does the same roof get bids 40% apart?

Three reasons: (1) shingle grade — 30-year vs 50-year vs impact-rated is a real cost spread. (2) Whether overhead/profit is itemized or hidden in the line items. (3) Whether the bid includes new flashing, ridge vents, and drip edge or just reuses what's there. Compare bids on like-for-like materials.

What's a fair contractor markup?

20-25% overhead + profit is industry standard for residential roofing. Below 15% means corners are getting cut somewhere (uninsured labor, no warranty, shaky business). Above 30% on a straightforward reroof should have a justification (specialty material, hard access, premium warranty).