Calculate roof area, materials needed, and project costs for any roof type. Get accurate estimates for shingles, metal, tile, and more.
Convert between pitch ratio and degrees
A roofing square is a standardized unit of measurement in the roofing industry that equals 100 square feet. Roofing materials are typically priced and sold by the square, making it easier to estimate costs. For example, if your roof measures 2,400 square feet, you would need 24 squares of material.
Roof pitch (slope) significantly impacts the actual roof area. A steeper pitch means more surface area to cover. The pitch multiplier accounts for this:
| Material | Cost per Square | Lifespan | Pros | Cons |
|---|---|---|---|---|
| Asphalt Shingles | $85-150 | 15-30 years | Affordable, easy installation | Shorter lifespan |
| Metal Roofing | $250-400 | 40-70 years | Durable, energy efficient | Higher upfront cost |
| Clay Tile | $400-600 | 50-100 years | Very durable, fire resistant | Heavy, expensive |
| Slate | $600-1000 | 75-200 years | Longest lifespan, beautiful | Very expensive, heavy |
| Wood Shake | $350-500 | 25-40 years | Natural look, insulation | Requires maintenance |
Roofing costs are measured per "square" (100 sq ft). These prices include materials only. Labor typically adds $1.50×$3.50 per sq ft depending on roof pitch and regional labor rates:
| Roofing Material | Material Cost/Sq | Installed Cost/Sq | Lifespan | Best For |
|---|---|---|---|---|
| 3-Tab Asphalt Shingles | $30×60 | $80×150 | 20×25 years | Budget replacement |
| Architectural Asphalt | $90×120 | $150×250 | 25×30 years | Best value for most homes |
| Metal (Steel Panels) | $100×200 | $200×400 | 40×70 years | Long-term investment |
| Standing Seam Metal | $200×350 | $350×600 | 50+ years | Premium homes, snow regions |
| Clay / Concrete Tile | $200×400 | $400×900 | 50+ years | Southwest, Mediterranean style |
| Slate | $600×1,200 | $900×1,800 | 75×100+ years | Historic/luxury homes |
To measure your roof: 1) Measure the length and width of each roof plane at ground level, 2) Multiply length × width for each section, 3) Add all sections together, 4) Multiply by the pitch multiplier for your roof's slope, 5) Add 10-15% for waste. For safety and accuracy, consider hiring a professional to measure complex roofs.
Ideal roof pitch depends on climate: Heavy snow areas need steeper pitches (6:12 or higher) for snow shedding. High wind regions benefit from 4:12 to 6:12 pitches. Hot, dry climates can use lower pitches (2:12 to 4:12). Heavy rain areas need at least 4:12 pitch. Always check local building codes for minimum pitch requirements.
Standard three-tab shingles come 3 bundles per square (100 sq ft). Architectural shingles typically come 3-4 bundles per square. Calculate: (Total roof area × 100) × bundles per square + 10% waste. For a 2,000 sq ft roof with 3 bundles per square: (2,000 × 100) × 3 = 60 bundles, plus 6 for waste = 66 bundles total.
Professional roofing labor typically includes: old roof removal and disposal, deck inspection and repairs, underlayment installation, ice and water shield in valleys, shingle installation, ridge cap installation, flashing around chimneys and vents, cleanup and debris removal. Labor costs range from $2-5 per sq ft depending on roof complexity and region.
Most residential roofs take 1-3 days to replace. Factors affecting timeline: Simple gable roof (1-2 days), complex roof with multiple valleys (3-5 days), weather delays, roof size (larger = longer), material type (tile and slate take longer), structural repairs needed. Professional crews typically complete 30-40 squares per day in ideal conditions.
Replace if: roof is over 20 years old, widespread damage (more than 30%), multiple leaks, curling or missing shingles throughout, failed deck structure, or planning to sell soon. Repair if: localized damage, roof is less than 10 years old, minor leaks in one area, storm damage in specific section. Get professional inspections to assess roof condition.
Late spring through early fall is ideal for roofing. Best conditions: temperatures 45-85×F for proper shingle sealing, dry weather (no rain forecasted), moderate wind speeds. Avoid: extreme heat (adhesive fails), freezing temperatures (shingles crack), rainy seasons. Fall is often the best time: moderate temperatures, lower humidity, contractors less busy. Emergency repairs can be done year-round.