Roof Replacement Cost Calculator
Estimate turnkey roof replacement costs per roofing square across architectural shingles, metal, tile, and slate materials.
Roof Dimensions & Material Options
๐ Roofing Industry Rule
Roofers price projects in "squares" (1 square = 100 square feet of roof surface). Always confirm your written contract includes ice & water shield in valleys, synthetic underlayment, new chimney flashing, and drip edge protection.
Roof Replacement Cost Formula
Roofing Squares = (Ground Footprint / Stories ร Overhang 1.15 ร Pitch Multiplier ร 1.10 Waste) / 100; Total Cost = Roofing Squares ร (Material + Tear-Off $/square) + Decking + Permits- Roofing Square: Standard industry unit equal to exactly 100 square feet of finished roof surface area.
- Pitch Multiplier: Steeper roofs require more surface materials and fall protection (1.06 for low slope, 1.18 for medium, 1.35 for steep).
- Material Rate: Turnkey installed price per square ($380 3-tab, $490 architectural, $980 standing seam metal, $1,350 tile).
- Tear-Off & Dumpster: Removal and disposal of existing shingle layers (typically $100-$120 per square).
- Decking Replacement: Rotted 4x8 CDX plywood replacement sheets identified after tear-off (~$90/sheet).
Step-by-Step Worked Example
Calculation Steps:
- Roof Surface Area = (1,100 ร 1.15 ร 1.18 ร 1.10 waste) = 1,642 sq ft = 17 Roofing Squares
- Core Shingle Installation = 17 squares ร $490.00 = $8,330.00
- Tear-Off & Dumpster Disposal = 17 squares ร $110.00 = $1,870.00
- Plywood Decking & Permit Fees = $180.00 (Decking) + $430.00 (Permits/Venting) = $610.00
- Total Turnkey Roof Replacement Cost = $8,330 + $1,870 + $610 = $10,810.00 ($636 / square)
How to Use This Calculator
- 1Enter the heated square footage of your home and select the number of stories.
- 2Choose the roof pitch: Low Slope (walkable), Medium (standard residential), or Steep (harnesses required).
- 3Select your roofing material type with your active currency.
- 4Leave the Tear-Off box checked if existing shingles must be stripped down to the plywood decking.
- 5Review the itemized labor, material, dumpster, and plywood decking breakdown.
Assumptions & Limitations
- Assumes work is performed by licensed, insured roofing contractors following manufacturer warranty specifications.
- Includes new synthetic felt underlayment, ice and water shield in valleys, and drip edge flashing.
- Does not include major rafter framing or structural truss reconstruction.
Frequently Asked Questions
What is a "roofing square"?
A roofing square is the universal unit of measurement in residential roofing, equal to 100 square feet of roof surface. For example, a 2,000 sq ft roof equals 20 roofing squares.
Can you shingle over an existing roof to save money?
While building codes in some municipalities allow up to two shingle layers, roofing experts strongly recommend against it. Shingling over old roofs prevents inspecting rotted decking, traps heat (shortening shingle life by 20-30%), and voids many manufacturer warranties.
How long do different roofing materials last?
Standard 3-tab asphalt lasts 15 to 20 years, architectural shingles last 25 to 30 years, standing seam metal roofs last 40 to 70 years, and concrete/clay tiles or natural slate can last 50 to 100+ years.
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