footprint × pitch geometry × published bands
Roof Cost Calculator
Five inputs, one line-item estimate sheet. Every number traces to the documented model below — so when a contractor's bid lands, you know whether it sits inside the band or needs explaining.
Job inputs
Footprint, not living area — a two-story 2,400 sq ft house often has a ~1,200 sq ft footprint.
RoofQuoted · Estimate Benchmark
Architectural (Dimensional) Shingles
6/12 — the most common pitch · Moderate roof · with tear-off
Typical published bands — not a quote. Real bids vary by region, access, and scope. Bids far outside this band deserve questions.
How the model works
Every output above is computed from four published inputs — nothing hidden, nothing tuned per visitor:
- Roof area from geometry. A pitched roof over a flat footprint has area footprint × √(1 + (rise/run)²). We publish the multipliers: 4/12 → ×1.06, 6/12 → ×1.12, 8/12 → ×1.2, 10/12 → ×1.3, 12/12 → ×1.41. Divide by 100 to get squares, roofing's unit of measure.
- Material bands per square, installed. Typical published bands per square (materials + labor): 3-Tab Asphalt Shingles $450–$650; Architectural (Dimensional) Shingles $550–$850; Standing-Seam Metal $900–$1500; Corrugated / Exposed-Fastener Metal $600–$950; Cedar Shake $900–$1600; Clay Tile $1200–$2500; TPO Membrane (Flat / Low-Slope) $550–$900.
- Complexity multiplier, labeled. Simple ×1.00 (basic gable or hip, few penetrations, one story); Moderate ×1.15 (a few valleys/dormers, chimney, two stories); Complex ×1.30 (many valleys, skylights, turrets, difficult access). Valleys, dormers, skylights, and stories all add labor.
- Tear-off as its own line. $100–$200 per square for removal and disposal of the existing roof.
The bands-not-quotes rule
These are typical published bands — quotes vary by region, access, story count, material grade, and tear-off scope. The calculator's job is not to replace a quote; it's to make a quote explain itself. A bid far below the band is usually missing something (insurance, permits, underlayment); a bid far above it should itemize why. Either way, run the fair-quote check before signing.
FAQ
How much does roof replacement cost?
Using typical published bands: asphalt shingles run $450–$850 per square (100 sq ft) installed depending on grade, metal $600–$1,500, cedar shake $900–$1,600, clay tile $1,200–$2,500, and TPO membrane $550–$900 — plus $100–$200 per square for tear-off. A 2,000 sq ft footprint at the common 6/12 pitch is about 22.4 squares, so most asphalt replacements land in the low-to-mid five figures. These are benchmark bands, not quotes: region, access, story count, and scope move real bids.
How do I calculate roof squares?
Multiply your home’s ground-floor footprint by a pitch multiplier, then divide by 100. The multiplier is pure geometry — a sloped plane over a flat footprint has more area: 4/12 pitch → ×1.06, 6/12 → ×1.12, 8/12 → ×1.20, 10/12 → ×1.30, 12/12 → ×1.41. Example: 2,000 sq ft footprint × 1.12 (6/12) = 2,240 sq ft of roof = 22.4 squares. Overhangs and complex shapes add a little; contractors measure precisely, which is why their squares belong on the written quote.
What does tear-off cost?
Removing and disposing of the existing roof typically runs $100–$200 per square as a published band, so 20–25 squares of tear-off is usually a $2,000–$5,000 line. It should always appear as its own line item on a quote — a bid that buries tear-off inside the shingle price cannot be benchmarked, and a second existing layer raises the cost.