Roofing Cost Calculator: Replacement Estimate
A new roof is one of the biggest home improvement investments you will make. Our roofing cost calculator gives you a ballpark estimate based on your home size, roof pitch, and material choice — so you can budget and compare quotes.
How Roof Pricing Works
Roofing is priced by the "square" — one square equals 100 square feet of roof area:
You cannot measure a roof from the ground by the footprint alone — the slope (pitch) adds surface area. Steeper roofs have more square footage.
Roof Pitch Multipliers
Use these multipliers to estimate roof area from footprint:
- 3/12 pitch — ×1.03 (low slope / flat-ish)
- 4/12 pitch — ×1.05
- 5/12 pitch — ×1.08
- 6/12 pitch — ×1.12 (very common)
- 7/12 pitch — ×1.16
- 8/12 pitch — ×1.20
- 10/12 pitch — ×1.30 (steep)
- 12/12 pitch — ×1.41 (very steep)
Roofing Material Options
The material you choose dramatically affects both cost and lifespan:
- 3-tab asphalt shingles — lowest cost, ~20-25 year lifespan
- Architectural / dimensional shingles — most popular, 25-40 year lifespan
- Metal roofing — premium, 40-70 year lifespan, energy efficient
- Clay / concrete tile — very durable, 50-100+ year lifespan, heavy
- Wood shake — natural look, 25-30 year lifespan
- Slate — the most durable, 75-200+ years, highest cost
What Affects Cost?
- Roof size — the primary driver; larger roofs cost more
- Roof pitch — steeper roofs are more labor-intensive and dangerous
- Material choice — can range from $100 to $1000+ per square
- Tear-off — removing old roofing adds labor and disposal cost
- Roof complexity — more valleys, dormers, hips, and angles mean more labor
- Underlayment — synthetic felt, ice & water shield, etc.
- Flashing — metal pieces around chimneys, vents, skylights
- Permits — city or county permits required
- Location — labor costs vary regionally
Example: 1,500 sq ft Home
1,500 sq ft house, 6/12 pitch, architectural shingles, tear-off:
- Roof area: 1,500 × 1.118 = 1,677 sq ft (16.8 squares)
- Material cost: 16.8 × $180 = $3,024
- Labor cost: 16.8 × $150 = $2,520
- Tear-off: 16.8 × $50 = $840
- Waste (10%): ~$302
- Total estimate: ~$6,686
FAQ
How much does a new roof cost?
$5,000-$15,000 is typical for asphalt shingles on an average home. Metal or tile can be $15,000-$30,000+.
How long does a roof last?
Asphalt shingles: 20-30 years. Metal: 40-70 years. Tile/slate: 50-100+ years.
Should I tear off or overlay?
Tear-off is recommended for better warranty and to inspect decking. Most areas allow one overlay, but tear-off is always better long-term.
Disclaimer: This calculator provides a rough estimate. Actual costs vary significantly by location, contractor, roof complexity, and current material prices. Always get multiple professional quotes.