Roof Replacement Cost Calculator
Get an instant free estimate for roof replacement and installation.
How is Roof Replacement Cost Calculated?
Roofing costs are calculated by the Square (100 sq ft). The price depends on material, pitch (steepness), and layers to remove. On average, a new asphalt roof costs $450 - $650 per square installed.
Calculate Your Estimate
Project Location
Where is the project located?
Roof Area
Roof Material:
Roof Steepness:
Existing Layers to Remove:
Additional Options:
Key Factors Influencing Roof Replacement Rates
Material Choice
Asphalt Shingles: Most affordable and common.
Metal: Permanent solution, high upfront cost.
Tile/Slate: Very heavy, requires structural reinforcement, expenses.
Roof Pitch & Complexity
Walkable (4/12 - 6/12): Standard labor rates.
Steep (7/12 - 9/12): Requires more safety gear/staging (+15-25%).
Very Steep (10/12+): High risk, significantly slower work (+30-50%).
Average Cost Per "Square" (100 sq. ft.)
| Material | Cost Range (Installed) | Lifespan |
|---|---|---|
| Asphalt (3-Tab) | $350 – $450 / sq | 15-20 Years |
| Asphalt (Architectural) | $450 – $650 / sq | 25-50 Years |
| Metal (Ribbed) | $600 – $900 / sq | 40-60 Years |
| Metal (Standing Seam) | $900 – $1,400 / sq | 50+ Years |
Labor & Preparation Costs
| Service | Cost Estimate | Why it's needed |
|---|---|---|
| Tear-off (1 Layer) | $100 – $150 / sq | Removing old shingles/felts. |
| Decking Replacement | $60 - $90 / sheet | Replacing rotten plywood base. |
| Steep Charge | +15% to +50% labor | Safety ropes, slower install pace. |
How to Estimate Roof Replacement Cost Manually
If you cannot use the calculator above, follow these 4 steps to get a baseline estimate:
Step 1: Determine Roof Square Footage
Roofers measure in "Squares" (1 square = 100 sq. ft.). To get sq. ft., measure your home's footprint (L x W) and multiply by a pitch factor (1.05 for flat/low, 1.15 for medium, 1.3+ for steep).
Step 2: Check Existing Layers
Check how many layers of shingles are currently on the roof. Building codes typically allow max 2 layers. Removing old layers adds $1-$2 per sq. ft. to the cost.
Step 3: Select Material
Asphalt Shingles (3-Tab or Architectural) are the standard budget option. Metal (Standing Seam) offers longevity but costs 2-3x more.
Step 4: Apply the Formula
Use this industry standard formula for a rough quote:
(Roof Sq Ft × Price Per Sq Ft installed) + Tear-off Fees = Total Cost
Example: 2,000 sq. ft. roof, asphalt shingles ($4.50/sq ft installed), 1 layer tear-off ($1.00/sq ft): (2000 × 4.50) + (2000 × 1.00) = $11,000.
Frequently Asked Questions
How do I know if I need a full replacement or just a repair?
If shingles are curling, missing, or losing granules over large areas, or if the roof is over 20 years old, replacement is likely needed. Isolated leaks or storm damage can often be repaired.
What is a 'Square' in roofing terms?
A 'Square' is a unit of measurement equal to 100 square feet. A 2,000 sq. ft. roof is 20 Squares.
Can I put a new roof over my old one (Overlay)?
Yes, if you only have one layer of shingles and the decking is sound. However, a full tear-off is recommended to inspect for water damage and ensures the new roof lasts longer.
How long does a roof replacement take?
An average asphalt shingle roof takes 1-3 days to replace, weather permitting. Metal or tile roofs may take longer (3-7 days).
What is 'flashing' and why is it important?
Flashing is metal material installed at joints (chimneys, vents, valleys) to prevent water intrusion. Re-using old flashing is a common cause of leaks in new roofs.
Does homeowners insurance cover roof replacement?
If the damage is caused by a covered peril like hail, wind, or fire, yes. Insurance typically does not cover replacement due to age or wear and tear.
What is the difference between 3-tab and architectural shingles?
3-tab shingles are flat and uniform (cheaper, 15-20 yr life). Architectural (dimensional) shingles are thicker, look textured, and last longer (25-30+ yrs).
Is proper ventilation necessary?
Absolutely. Proper ridge and soffit vents extend the life of your shingles by preventing heat and moisture buildup in the attic, which can cook the roof from the inside out.
How much does a metal roof cost compared to asphalt?
Expect to pay 2 to 3 times more for a standing seam metal roof compared to asphalt shingles, but it can last 50+ years versus 20 years.
What if I find rotten wood (decking) after tear-off?
Rotten decking (plywood/OSB) must be replaced before new shingles are installed. Contractors typically charge per sheet ($60-$100/sheet) for this unforeseen cost.