Roofing Calculator
Estimate roofing materials and total cost for your home based on roof area, pitch and material type.
How to use the Roofing Calculator
- Enter your inputs into the Roofing Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The roofing estimate
Squares = Roof area / 100 · · · Material cost = Squares × Price/square · · · Add 10–15% waste
Roofing is sold by "square" (100 sq ft). Total area depends on roof pitch — steeper roofs have more surface area than the footprint suggests. Multiply footprint by pitch factor.
Worked example
A 1,500 ft² home with 6/12 pitch roof: pitch factor 1.118 → roof area ≈ 1,677 ft² = 16.77 squares + 10% waste = 18.5 squares. Asphalt shingles at $115/square: $2,128 for shingles only. Total job (materials + labor) typically 3–5×: $6,000–10,000.
Frequently asked questions
What is "pitch factor"?
A multiplier that converts horizontal footprint to actual roof surface area. 4/12 pitch: 1.054; 6/12: 1.118; 8/12: 1.202; 12/12 (45°): 1.414.
How long do different roofing materials last?
20–25 years asphalt shingles; 30–50 years metal; 50+ years tile or slate. Climate, ventilation and installation quality affect actual lifespan significantly.
When should I replace my roof?
When repairs become more frequent, granule loss accelerates, shingles curl/crack visibly, or after major storm damage. Inspect annually after age 15.