How to Use This Calculator
Work through the input fields from top to bottom to build your estimate. Each field refines the calculation to reflect your specific project, so the more accurate your inputs, the more useful the result.
- Roof Area (sq ft): Enter the total square footage of your roof surface, not the footprint of your home. A roof with a steep pitch covers more surface area than the floor plan suggests. If you don't know the exact number, measure your home's footprint and multiply by a pitch factor (1.0 for flat, 1.15 for moderate, 1.3 for steep).
- Number of Stories: Taller homes require more safety equipment, scaffolding, and labor time. A two- or three-story job typically adds 10 to 20 percent to the labor portion of the estimate.
- Roofing Material: Material choice is the single biggest cost variable. Standard 3-tab asphalt shingles sit at the low end, while natural slate or standing seam metal sit at the high end. Select the material you are planning to install or want priced.
- Roof Pitch: Steeper roofs are harder to work on safely and require more material due to the greater surface area. Contractors charge premium labor rates for pitches above 7/12.
- Existing Layers to Remove: Most building codes cap roofing layers at two. Tearing off one or two layers of old shingles adds disposal and labor costs. Choosing zero means either a new deck or a reroof over bare wood.
- Decking / Sheathing Repair: Hidden rot, water damage, or soft spots in the plywood deck are often discovered after tear-off. Selecting a repair level accounts for this common added expense.
- Your Region: Labor and material costs vary significantly by geography. Urban Northeast markets run higher than rural Southeast markets. Pick the region closest to your home.
- Add-Ons and Special Conditions: Check any items that apply to your project. Gutters, flashing, permits, and ventilation upgrades are commonly bundled into a reroof project and can meaningfully affect the final price.
Once you have filled in all the fields, click "Calculate Cost" to see your low, mid, and high estimate along with a line-item breakdown. Use these numbers as a starting point when gathering quotes from licensed roofing contractors in your area.
What Is a Reroof and When Do You Need One?
A reroof is the complete removal and replacement of your home's roofing system. It typically includes tearing off old shingles or other existing roofing material, inspecting and repairing the plywood or OSB decking underneath, installing new underlayment, and applying fresh roofing material from ridge to eave. A reroof is one of the most significant home improvement investments a homeowner can make, and for good reason: your roof is the first line of defense against water, wind, heat, and cold.
Most roofs have a useful lifespan that depends heavily on material. Standard asphalt shingles typically last 20 to 30 years. Architectural shingles stretch that range to 30 to 40 years. Metal roofing can last 40 to 70 years, and premium materials like natural slate or clay tile can outlast the home itself when properly maintained. When a roof approaches the end of its rated lifespan, or when it suffers damage that affects a large portion of its surface, a full replacement is usually more cost-effective than repeated patching.
Homeowners often need a reroof when they notice granule loss on asphalt shingles, curling or buckling shingle edges, visible daylight through the attic, water stains on ceilings or walls, sagging sections of the roof deck, moss or algae growth that has penetrated the material, or after a major storm event involving hail or high winds. A roofing contractor can perform an inspection to confirm whether repair or full replacement is the better path forward, but once delamination, widespread cracking, or structural deck damage is present, a reroof is almost always the right answer.
Average Reroof Cost Ranges
Reroof costs vary widely based on the size of the home, the material chosen, regional labor rates, and project complexity. The table below shows general cost ranges for a typical single-family home (roughly 1,500 to 2,500 sq ft of roof surface). These figures reflect full tear-off and replacement with standard installation practices and do not include major deck repairs or premium add-ons.
| Project Scope / Material | Low Estimate | Mid Estimate | High Estimate |
|---|---|---|---|
| Small Home, Asphalt 3-Tab (1,000–1,500 sq ft) | $4,500 | $6,500 | $9,000 |
| Medium Home, Architectural Shingles (1,500–2,500 sq ft) | $8,000 | $12,000 | $17,000 |
| Large Home, Architectural Shingles (2,500–3,500 sq ft) | $13,000 | $19,000 | $26,000 |
| Medium Home, Metal Standing Seam (1,500–2,500 sq ft) | $18,000 | $26,000 | $38,000 |
| Medium Home, Clay or Concrete Tile (1,500–2,500 sq ft) | $20,000 | $30,000 | $45,000 |
| Medium Home, Natural Slate (1,500–2,500 sq ft) | $28,000 | $45,000 | $70,000 |
| Flat Roof Replacement, TPO or EPDM (1,000–2,000 sq ft) | $5,000 | $8,500 | $14,000 |
These are rough benchmarks. Your actual cost will depend on local labor rates, roof complexity, the number of valleys and penetrations, and any additional work discovered after tear-off. Always request at least three detailed quotes from licensed roofing contractors before committing to a project.
Frequently Asked Questions
How long does a reroof project typically take?
Most residential reroof projects are completed in one to three days for a standard single-story home with an uncomplicated roof shape. Larger homes, steep pitches, complex roof layouts with many valleys and dormers, or projects that require significant deck repairs can stretch to four or five days. Weather delays are common, particularly in spring and fall when roofing season overlaps with rain and wind.
Can I put new shingles over my existing roof?
In some cases, yes. Applying new shingles over one existing layer (sometimes called a "recover" or overlay) is permitted by many building codes and can reduce labor and disposal costs by $1,000 to $3,000. However, most roofing professionals recommend a full tear-off because overlaying hides existing damage, adds weight to the structure, and typically voids the manufacturer's warranty on the new shingles. If there are already two layers on the roof, local code in most jurisdictions requires full tear-off before any new material can be installed.
Does homeowners insurance cover a reroof?
It depends on the cause of the damage. Most homeowners insurance policies cover sudden, accidental damage from events like hail, wind, or falling trees. They generally do not cover wear and tear, age-related deterioration, or deferred maintenance. If your roof was damaged in a storm, contact your insurer before signing a contract with a roofing company. An adjuster will inspect the damage and determine whether a claim is payable. Be cautious of contractors who pressure you to file a claim before an inspection or who offer to waive your deductible, as this is fraudulent in most states.
Do I need a building permit to replace my roof?
Most jurisdictions require a building permit for a full roof replacement, though the rules vary by city and county. Permits typically cost between $150 and $500 and allow the local building department to inspect the completed work. A licensed contractor will usually pull the permit on your behalf as part of the job. Skipping the permit can create problems when you sell the home or file an insurance claim, so it is worth confirming requirements with your local building department before the project starts.
What is the best roofing material for the money?
Architectural (dimensional) asphalt shingles offer the best balance of cost, durability, and appearance for most homeowners. They typically cost 15 to 25 percent more than basic 3-tab shingles but carry longer warranties (30 to 50 years), perform better in high-wind conditions, and have a more attractive layered look. Metal roofing is a strong long-term value choice for homeowners who plan to stay in the home for decades, given its 40 to 70-year lifespan and low maintenance requirements. Premium materials like slate and tile make the most sense when the home's architecture calls for them or when you are restoring a historic property.
What should I look for when hiring a roofing contractor?
Start by verifying that the contractor holds a valid state license and carries both general liability insurance and workers' compensation coverage. Ask for proof of insurance directly, not just verbal confirmation. Request a written contract that specifies the scope of work, materials (including brand and product line), warranty terms, payment schedule, and a timeline. Get at least three bids. Be wary of unusually low quotes, demands for large upfront deposits, door-to-door solicitations after storms, and contractors who are not local or do not have a physical business address.
How much does deck repair typically add to the cost?
Roofers typically charge between $60 and $100 per sheet (4x8 ft panel) to replace damaged plywood or OSB decking, including materials and labor. On a typical home, replacing 10 percent of the deck might run $500 to $1,000, while extensive rot affecting 25 to 40 percent of the deck can add $2,000 to $5,000 or more. Since damage is often hidden beneath old shingles, a reputable contractor will document any discovered issues and provide a change order before proceeding with repairs, rather than billing you for unknown quantities after the fact.
What is the difference between underlayment options?
Underlayment is the moisture barrier installed between the roof deck and the shingles. Standard 15 lb or 30 lb felt is the traditional and least expensive option, but it can tear during installation and is less resistant to UV exposure if left uncovered for more than a few days. Synthetic underlayment is lighter, stronger, more slip-resistant for installers, and generally more water-resistant. Self-adhered or peel-and-stick underlayment (often called ice and water shield) provides the highest level of protection, particularly in valleys, eaves, and around penetrations. In cold climates, local code often requires ice and water shield along the first few feet of each eave to prevent ice dam damage.