How this roofing calculator works
Roofers do not price a roof by the size of your house. They price it by the sloped surface of the roof, counted in squares. One square is 100 square feet.
- The calculator adds your eave overhang to the length and width to get the footprint the roof covers.
- It multiplies that footprint by the pitch factor. A 6/12 roof has 11.8% more surface than its footprint.
- It adds waste for cutting: 10% on a gable, 15% on a hip, 20% on a cut-up roof.
- It divides by 100 to get squares, then applies a 2026 price range for the material you picked.
Pitch factor = √(1 + (rise / 12)²)
2026 installed cost per square by material
These national ranges cover tear-off of one layer, new underlayment, flashing and labor on a walkable roof. They are planning numbers, not quotes.
| Material | Per square installed | 2,000 sq ft roof | Lifespan |
|---|---|---|---|
| 3-tab asphalt | $400 to $550 | $8,000 to $11,000 | 15 to 20 yrs |
| Architectural asphalt | $450 to $700 | $9,000 to $14,000 | 25 to 30 yrs |
| Exposed-fastener metal | $600 to $1,000 | $12,000 to $20,000 | 30 to 45 yrs |
| Standing seam metal | $900 to $1,600 | $18,000 to $32,000 | 40 to 70 yrs |
| Concrete tile | $800 to $1,400 | $16,000 to $28,000 | 40 to 50 yrs |
| Clay tile | $1,000 to $2,000 | $20,000 to $40,000 | 50 to 100 yrs |
| Natural slate | $1,500 to $3,000 | $30,000 to $60,000 | 75 to 100+ yrs |
Need a deeper breakdown by state, tear-off layers and add-ons? Use the roof replacement cost calculator.
Want a pro to confirm these numbers?
Numbers look right? A licensed roofer can measure on site and give you an exact price.
What changes the price
- Pitch. Above 7/12, crews need harnesses and roof jacks. Expect 15% to 45% more labor. See the roof pitch calculator.
- Complexity. Valleys, dormers, skylights and chimneys mean more cuts, more flashing and more waste.
- Tear-off layers. A second layer of old shingles adds roughly $50 to $100 per square to remove and dump.
- Decking. Rotted sheathing is replaced per sheet, usually $70 to $120 each installed. Plan for 5 to 10 sheets on an older home.
- Location. Labor and code rules vary. Hurricane and hail zones often require upgraded fasteners or impact-rated shingles.
Measure your roof without climbing it
You do not need to get on the roof for a planning estimate.
- Measure the house length and width at the outside walls. Property records or a floor plan work too.
- Estimate pitch from the ground with a phone inclinometer app held against the gable edge, then convert with the pitch to degrees table.
- Measure one overhang from a ladder at the eave.
For material orders, use the roof square footage calculator and shingle calculator, which handle multiple roof planes.
Sources and further reading
- National Roofing Contractors Association (NRCA)
- Asphalt Roofing Manufacturers Association (ARMA)
- Insurance Information Institute: homeowners insurance basics
Frequently asked questions
How do I calculate how much roofing I need?
Multiply the house footprint (including overhangs) by the pitch factor for your roof slope, add 10% to 20% for waste, then divide by 100 to get squares. A 1,500 sq ft footprint at 6/12 pitch is about 1,677 sq ft of roof, or 18.5 squares with 10% waste.
How many bundles of shingles are in a square?
Most asphalt shingles come 3 bundles per square, so one bundle covers about 33.3 square feet. Some heavy designer shingles are 4 or 5 bundles per square. Check the wrapper.
How much does a new roof cost in 2026?
Most homes with architectural shingles land between $9,000 and $18,000. The national range runs from about $6,000 for a small, simple roof to $40,000 or more for tile, slate or large complex roofs.
Does roof pitch affect cost?
Yes. Pitch raises cost twice: a steeper roof has more surface area, and anything above about 7/12 needs safety gear and slower work, which adds 15% to 45% to labor.
Is this calculator accurate enough to order materials?
It is accurate for the math. The inputs are the weak point. Measure each roof plane, use the actual pitch and confirm with your supplier or roofer before you order.