How much does a new roof cost?

Roofing material costs (materials only, per square = 100 sq ft, before waste): Asphalt: ~$120/square. Metal: ~$400/square. Tile: ~$600/square. Slate: ~$1,200/square. This calculator adds a waste allowance on top (10% simple roofs, 15% moderate, 20% complex with dormers/valleys) before pricing materials, then adds labor, removal/disposal, and underlayment (see cost breakdown above) for the full installed price. Typical 2,000 sq ft house (20-25 squares before waste) installed total: Asphalt $4K-6K, Metal $10K-15K.

How long does a roof last?

Roof lifespan by material: Asphalt: 15-20 years (budget), 25-30 years (architectural). Metal: 40-70 years (steel/aluminum). Tile: 50+ years (clay/concrete, very durable). Slate: 75-100+ years (longest lasting, premium). Factors: climate, maintenance, installation quality, ventilation. Best value: Metal (50 years, moderate cost, low maintenance).

What is a roofing square?

Roofing square: 1 square = 100 sq ft of roof area. Not the same as sq ft (accounts for pitch/slope). Example: 1,200 sq ft flat roof = 12 squares. 1,200 sq ft with 6/12 pitch = 13.4 squares (pitch increases area). Why used: Standard measurement (materials sold per square). Easy math (20 squares × $200 = $4,000). Industry standard.

Why does roof complexity affect cost?

Hips, valleys, and dormers require more angled and irregular cuts, which wastes more material and slows installation. This calculator applies NRCA-standard waste allowances: 10% for simple gable roofs, 15% for moderate roofs with some hips/valleys, and 20% for complex roofs with dormers or multiple valleys. A complex roof can cost meaningfully more than a simple roof of the same footprint even with identical materials and pitch.

Construction Calculators

Roofing Calculator

Calculate roofing materials and costs for asphalt, metal, tile, and slate with pitch adjustments. Features roof area calculation in squares, material and labor cost breakdown, removal/underlayment costs, and lifespan comparisons.

How to Use the Roofing Calculator

Use the Roofing Calculator to roofing materials and costs for asphalt, metal, tile, and slate with pitch adjustments. Features roof area calculation in squares, material and labor cost breakdown, removal/underlayment costs, and lifespan comparisons.. Enter your values to get accurate, instant results tailored to your situation.

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Roofing Guide

Roof replacement planning

Expert Tips

Roof Replacement Costs $5,000-25,000+ (2,000 sqft): Asphalt shingles: $3.50-5.50/sqft installed ($7K-11K for 2,000 sqft). Metal: $7-12/sqft ($14K-24K). Tile: $10-18/sqft ($20K-36K). Flat roof membrane: $4-8/sqft. Includes: Tear-off, disposal, new shingles, underlayment, flashing, ridge vents.
Roof Area = Floor Area × Roof Pitch Multiplier: Flat roof (1/12 pitch): Floor area × 1.0. Low pitch (4/12): × 1.05. Medium (6/12): × 1.12. Steep (9/12): × 1.25. Very steep (12/12): × 1.41. Example: 2,000 sqft house, 6/12 pitch = 2,000 × 1.12 = 2,240 sqft roof area. Order materials by roof sqft, not floor sqft.
Add 10-15% Extra for Waste, Complex Roofs: Simple rectangular roof: +10%. Complex (multiple valleys, dormers, hips): +15-20%. Shingles sold in "squares" (100 sqft). 2,240 sqft roof + 15% = 2,576 sqft = 26 squares. Ridge cap, starter strips add 2-3 squares. Total order: 28-29 squares.
Roof Lifespan: Asphalt 15-30 Years, Metal 40-70 Years: Asphalt 3-tab: 15-20 years. Architectural shingles: 25-30 years. Metal: 40-70 years. Tile: 50-100 years. Longer-lasting = higher upfront but lower lifetime cost. Metal roof $20K lasts 50 years ($400/year) vs asphalt $10K lasts 20 years ($500/year).

Essential Fundamentals — Material selection

Roofing Materials

Asphalt Shingles: Pros: Affordable, easy install, widely available. Cons: Shorter lifespan (20-30 years), less energy-efficient. Cost: $90-150/square materials, $350-550/square installed. Best for: Budget-conscious, traditional look, moderate climates.
Metal Roofing: Pros: 40-70 year lifespan, energy-efficient (reflects heat), fire-resistant, low maintenance. Cons: Higher upfront cost, can dent, noise in rain. Cost: $700-1,200/square installed. Best for: Long-term investment, hot/snowy climates, modern aesthetic.

Advanced Strategies — Maximizing roof lifespan

Installation Quality

Ventilation Critical: Proper attic ventilation extends roof life by preventing heat/moisture buildup. Ridge vents + soffit vents = balanced airflow. Poor ventilation causes premature shingle failure, ice dams in winter.
Underlayment Matters: Synthetic underlayment lasts longer than felt paper. Ice and water shield on eaves, valleys, around chimneys prevents leaks. Spend extra on quality underlayment—it's leak insurance.
Contractor Selection: Get 3 quotes, check references, verify insurance. Cheapest bid often cuts corners (skip underlayment, reuse flashing). Quality install adds 5-10 years to roof life.

Frequently Asked Questions

How much does a new roof cost?: Roofing material costs (materials only, per square = 100 sq ft, before waste): Asphalt: ~$120/square. Metal: ~$400/square. Tile: ~$600/square. Slate: ~$1,200/square. This calculator adds a waste allowance on top (10% simple roofs, 15% moderate, 20% complex with dormers/valleys) before pricing materials, then adds labor, removal/disposal, and underlayment (see cost breakdown above) for the full installed price. Typical 2,000 sq ft house (20-25 squares before waste) installed total: Asphalt $4K-6K, Metal $10K-15K.
How long does a roof last?: Roof lifespan by material: Asphalt: 15-20 years (budget), 25-30 years (architectural). Metal: 40-70 years (steel/aluminum). Tile: 50+ years (clay/concrete, very durable). Slate: 75-100+ years (longest lasting, premium). Factors: climate, maintenance, installation quality, ventilation. Best value: Metal (50 years, moderate cost, low maintenance).
What is a roofing square?: Roofing square: 1 square = 100 sq ft of roof area. Not the same as sq ft (accounts for pitch/slope). Example: 1,200 sq ft flat roof = 12 squares. 1,200 sq ft with 6/12 pitch = 13.4 squares (pitch increases area). Why used: Standard measurement (materials sold per square). Easy math (20 squares × $200 = $4,000). Industry standard.
Why does roof complexity affect cost?: Hips, valleys, and dormers require more angled and irregular cuts, which wastes more material and slows installation. This calculator applies NRCA-standard waste allowances: 10% for simple gable roofs, 15% for moderate roofs with some hips/valleys, and 20% for complex roofs with dormers or multiple valleys. A complex roof can cost meaningfully more than a simple roof of the same footprint even with identical materials and pitch.