Roofing Calculator
Estimate a new roof from start to finish. Add each roof section (main house, garage, porch) with its own size and pitch, pick from nine roofing materials, and get the roof area, squares, materials to order, roof weight and the installed cost range — with a pitch and weight check, a roof plan, a side-by-side material comparison and a downloadable PDF.
| Material | Installed / sq ft | Est. total | Weight / sq | Lifespan | Cost / year |
|---|---|---|---|---|---|
| Enter your roof sections to compare | |||||
| Section | Footprint | Pitch | Roof area | Squares | Est. cost |
|---|---|---|---|---|---|
| Enter your roof sections to compare | |||||
How to use the roofing calculator
Four quick steps turn your roof sections and material choice into roof area, squares, materials to order, roof weight and a full installed cost — with a pitch and weight check, a roof plan, by-material and by-section tables, charts and a downloadable report.
Add your roof sections
Enter each section (main roof, garage, porch) with its own size and pitch, plus the overhang.
Pick a material
Choose from nine roofing materials, or enter your own quoted price per square foot.
Set complexity & tear-off
Pick simple, moderate or complex, the layers to remove and any decking replacement.
Read results & save a PDF
Get materials, weight, total cost, cost per square and cost per year, then download a report.
How a roof estimate is calculated
Each section’s footprint becomes real sloped area through the pitch, then area drives the squares, materials and installed cost, adjusted for complexity and steep-roof labor. Here is the exact math the calculator runs.
Worked example — 50 × 30 ft main roof, 12″ overhang, 6/12 pitch, architectural shingles, simple, 1 tear-off layer
Roof area: 1,664 × 1.118 ≈ 1,860 sq ft (18.6 squares) · +10% waste → 20.5 squares · 62 bundles
Roofing installed: $8,400–$13,000 (mid ≈ $10,700) · Tear-off: 18.6 × $150 ≈ $2,800
Total ≈ $13,500 · $7.25/sq ft · $725/square · life 25–30 yr
≈ $13,500 for a new architectural-shingle roof — about $7.25 per square foot, or roughly $490 a year over its 25–30 year life.
Roofing cost & material reference charts
Handy lookups for how the material and roof complexity change the installed cost, weight, lifespan and cost per year.
| Material | Installed / sq ft | Est. total | Weight / sq | Lifespan | Cost / year |
|---|---|---|---|---|---|
| Asphalt 3-tab | $3.50–$5.50 | ~$11,200 | 230 lb | 15–20 yr | ~$640 |
| Architectural shingles | $4.50–$7.00 | ~$13,500 | 320 lb | 25–30 yr | ~$490 |
| Metal (exposed fastener) | $5.00–$9.00 | ~$15,800 | 120 lb | 30–45 yr | ~$420 |
| Standing seam metal | $9.00–$16.00 | ~$26,000 | 130 lb | 40–70 yr | ~$475 |
| Wood shakes | $7.00–$13.00 | ~$21,400 | 350 lb | 25–35 yr | ~$715 |
| Clay tile | $10.00–$20.00 | ~$30,700 | 1,100 lb | 50–100 yr | ~$410 |
| Concrete tile | $8.00–$14.00 | ~$23,300 | 950 lb | 40–50 yr | ~$515 |
| Slate | $15.00–$30.00 | ~$44,700 | 1,000 lb | 75–150 yr | ~$400 |
| Flat roof (TPO / EPDM) | $5.00–$9.00 | ~$15,800 | 50 lb | 20–30 yr | ~$635 |
The cheapest up front isn’t always cheapest per year: slate and clay cost the most to install but their very long life brings the cost per year back down near asphalt. Heavy tile and slate (about 1,000 lb/sq) may need the framing checked.
| Complexity | Waste | Cost factor | Examples |
|---|---|---|---|
| Simple | 10% | 1.00× | Plain gable, few penetrations |
| Moderate | 15% | 1.10× | Hip roof, a dormer or two |
| Complex | 20% | 1.25× | Many valleys, dormers, angles |
Complexity raises both the waste (more cut-off material) and the labor factor. A complex cut-up roof can cost about 25% more to install than a simple one of the same area.
| Material | Minimum slope | Note |
|---|---|---|
| Standing seam metal | ¼:12 | Lowest-slope option |
| Metal (exposed fastener) | ½:12–3/12 | Lap sealant below 3/12 |
| Asphalt shingles | 2/12 | Double underlayment to 4/12 |
| Clay / concrete tile | 2½:12 | Double underlayment to 4/12 |
| Wood shakes / slate | 4/12 | Steeper is better for shedding |
| Flat membrane (TPO/EPDM) | flat–¼:12 | For low slopes only |
The calculator checks each section’s pitch against the material minimum and flags anything too low for the material you picked.
What the roofing calculator gives you
Your roof sections and a material choice give you a full replacement estimate, not just an area.
Roofing at a glance
Who uses a roofing calculator
From a first budget to comparing materials and quotes, the same calculator prices the whole roof.
Planning a roof replacement and wants a realistic all-in number before calling contractors.
- Add each roof section
- Try a few materials
- Check cost per year
Deciding between shingles, metal, tile or slate and wants cost, weight and lifespan side by side.
- Compare all materials
- Watch the weight
- Balance cost vs life
Pricing a job and needs area, squares, tear-off, decking and a total across every section.
- Enter your quote rate
- Set complexity
- Export the PDF
Tips for a roof replacement estimate
A trustworthy roof budget comes from real sections, the right complexity and planning for what’s found under the old roof.
Roofing calculator FAQ
Quick answers about roof cost, area, materials, weight, lifespan and tear-off.
For a typical 50 × 30 ft house (about 1,860 sq ft of roof), a new architectural-shingle roof runs roughly $13,000 to $14,000 installed, or about $7 per square foot, including tear-off of one layer.
Budget 3-tab shingles are nearer $11,000, while premium materials like slate can top $40,000 on the same roof.
Multiply the footprint (length plus overhang × width plus overhang) by the slope factor, which is √(1 + (pitch÷12)²). A 52 × 32 ft footprint at 6/12 is about 1,860 sq ft of roof, or 18.6 squares.
Add each roof section separately and total them.
Asphalt 3-tab shingles are the cheapest common roofing at roughly $3.50 to $5.50 per square foot installed, followed by architectural shingles.
They also have the shortest life (15 to 20 years for 3-tab), so the cheapest up front isn’t always the cheapest per year.
Slate lasts the longest, 75 to 150 years, followed by clay tile at 50 to 100 years and standing-seam metal at 40 to 70. Asphalt shingles last 15 to 30 years.
Spread over its life, a long-lived material can have a competitive cost per year despite a high up-front price.
Asphalt shingles weigh about 230 to 320 lb per square (100 sq ft), metal roughly 120 to 130, wood shakes about 350, concrete tile around 950, and clay tile or slate about 1,000 to 1,100 lb per square.
Heavy tile and slate often need the roof framing checked or reinforced.
A roofing square is 100 square feet of roof surface. Roofers price materials, labor and tear-off by the square.
A 2,000 sq ft roof is 20 squares.
Most codes allow up to two layers of asphalt shingles, so a second layer can sometimes go over the first. Tile, slate and metal usually need a full tear-off, and tearing off lets the crew inspect and repair the decking.
Removal runs about $100 to $200 per roofing square per layer.
After the material itself, the biggest drivers are roof complexity (valleys, dormers and hips raise waste and labor), steep pitch (slower work above about 7/12), tear-off of multiple layers, and any rotten decking found once the old roof is off.
Permits and new flashing or gutters add more.
Planning estimate only — get local quotes. Installed prices are rough national ballpark ranges in US dollars and vary widely by region, contractor, access and roof condition, so enter your own quote if you have one. Roof area = footprint × √(1 + (pitch÷12)²), and 1 roofing square = 100 sq ft. Steep roofs and complex roofs carry a labor markup, and weight, lifespan and cost-per-year figures are typical ranges. Minimum slopes follow common building-code rules for each material; heavy tile and slate may need the roof framing checked. Always follow the manufacturer’s instructions and your local building code.