This roof replacement cost calculator helps you set a realistic budget before requesting contractor quotes. Enter your roof size, pitch, cost per square foot, waste factor, and optional tear-off and repair allowances. The calculator returns an itemized low, typical, and high cost range so you know exactly where each dollar goes.
- Choose your area mode. Select "Home footprint" if you know the ground floor area from tax records or a floor plan. Select "Direct roof area" if you already have measured square footage from a drone survey, satellite tool, or contractor report. Direct measurement is more accurate for complex roof shapes with hips, dormers, and valleys.
- Enter pitch and eaves (footprint mode). Roof pitch converts flat footprint to actual surface area. A 6/12 pitch adds about 12% to the area. Eaves allowance adds overhangs that extend past the exterior walls, usually 3% to 8%.
- Enter your installed cost per square foot. Use a rate from a contractor quote, local average, or material scenario. Asphalt shingles typically run $5 to $9/sq ft installed. Metal runs $8 to $16/sq ft. Tile and slate can reach $10 to $25/sq ft in 2026.
- Set a waste factor. Use 10% for simple gable roofs with minimal cuts. Use 15% to 20% for complex roofs with hips, valleys, dormers, chimneys, or skylights. Waste above 20% usually means you should measure each roof section separately.
- Add tear-off and repair allowances. If you're removing old roofing, enter the tear-off rate and number of existing layers. Multiple layers cost more to remove. The repair allowance covers decking damage, flashing, underlayment upgrades, permits, and disposal fees that contractors sometimes quote separately.
- Click Estimate replacement cost and review the itemized breakdown before comparing contractor bids line by line.
Pro tip: measure complex roofs by section instead of relying only on home footprint. A drone measurement or satellite tool gives you actual roof area and avoids the guesswork of pitch and eaves adjustments. Most homeowners underestimate roof area by 10% to 25% when using footprint alone.
Common mistake: comparing bids that include different line items. One quote might include tear-off, disposal, and new underlayment while another covers only shingles and labor. Use the checklist below to verify that every bid covers the same scope before choosing the lowest number.
Quote comparison checklist
Before signing a roofing contract, confirm each bid includes these line items. Missing items often explain why one quote is much lower than another.
| Line item | What to verify |
|---|---|
| Tear-off and disposal | Number of layers removed, dumpster included or separate |
| Underlayment | Synthetic or felt, ice and water shield in valleys and eaves |
| Flashing | Valleys, walls, chimneys, pipe boots, and step flashing |
| Decking repair | Price per sheet if plywood or OSB needs replacement |
| Ridge and starter | Ridge cap shingles and starter strip included or extra |
| Ventilation | Ridge vent, soffit vents, or box vents included |
| Permits and inspection | Contractor pulls permit or homeowner responsibility |
| Warranty | Manufacturer warranty length and workmanship guarantee |
A low quote that excludes disposal, underlayment, or flashing can end up costing more once change orders come in. Run this roof replacement cost calculator with each contractor's scope to see the difference.
Installed cost ranges by material (2026)
Use these planning ranges to choose an installed rate input. Prices include material and labor for a standard one-story gable roof.
| Roofing material | Installed $/sq ft | Typical lifespan |
|---|---|---|
| 3-tab asphalt shingles | $4.50 to $7.00 | 15 to 20 years |
| Architectural asphalt shingles | $5.50 to $9.00 | 25 to 30 years |
| Standing seam metal | $8.00 to $16.00 | 40 to 70 years |
| Concrete tile | $10.00 to $18.00 | 40 to 50 years |
| Clay tile | $12.00 to $25.00 | 50 to 100 years |
| Natural slate | $15.00 to $30.00 | 75 to 150 years |
| Flat roof (TPO/EPDM) | $5.00 to $10.00 | 20 to 30 years |
Steep roofs, second stories, and complex shapes push costs toward the upper range. Get at least three itemized bids and run each through this roof replacement cost calculator to compare on the same baseline.