A new roof is one of the biggest bills a homeowner faces, and the quotes can be thousands of dollars apart for what looks like the same job. The price is not a mystery, though. It comes down to five things: how big the roof is, how steep it is, what it is made of, what has to come off first and how complicated the shape is. This guide walks through each one so you can set a budget and read a quote with confidence.
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Open the roofing cost calculatorStep 1: work out the size of the roof
Roofers do not price by the floor area of your house. They price by the surface of the roof, measured in squares: one square is 100 square feet. Start with the footprint of the house, which is the ground floor area including an attached garage. A two-story house with 2,400 square feet of living space usually has a footprint of about 1,200 to 1,400 square feet.
Then add the overhangs. Eaves and gable ends stick out past the walls, which adds about 10 percent. A 1,800 square foot footprint becomes about 1,980 square feet before pitch is counted.
Step 2: account for the pitch
Pitch is how many inches the roof rises for every 12 inches it runs. A steeper roof covers the same footprint with more surface:
| Pitch | Multiply by | 1,980 sq ft becomes |
|---|---|---|
| 4/12 | 1.054 | 2,087 sq ft (20.9 squares) |
| 6/12 | 1.118 | 2,214 sq ft (22.1 squares) |
| 8/12 | 1.202 | 2,380 sq ft (23.8 squares) |
| 10/12 | 1.302 | 2,578 sq ft (25.8 squares) |
| 12/12 | 1.414 | 2,800 sq ft (28.0 squares) |
Pitch also changes the labor. Up to about 6/12 a crew can walk the roof. From 8/12 they need harnesses and roof jacks, and every task takes longer, so the price per square rises on top of the extra material.
Step 3: choose the material
Material is the biggest single swing in the price. Typical installed prices in the United States in 2026:
| Material | Per sq ft installed | 22 squares (2,200 sq ft) | Life |
|---|---|---|---|
| 3-tab asphalt | $4.00 to $5.50 | $8,800 to $12,100 | 15 to 20 years |
| Architectural asphalt | $4.75 to $7.50 | $10,450 to $16,500 | 25 to 30 years |
| Corrugated metal | $6 to $10 | $13,200 to $22,000 | 25 to 40 years |
| Wood shakes | $8 to $14 | $17,600 to $30,800 | 25 to 30 years |
| Concrete or clay tile | $9 to $20 | $19,800 to $44,000 | 50 years or more |
| Standing seam metal | $10 to $16 | $22,000 to $35,200 | 40 to 70 years |
For most houses, architectural shingles are the sensible middle: better wind resistance and a longer warranty than 3-tab for a small premium. If you plan to stay for decades, compare the cost per year of life, not just the up-front price; a metal roof that lasts 50 years can cost less per year than two shingle roofs.
Step 4: tear-off or overlay
Removing the old roof costs about $1 to $2 per square foot for each layer, including disposal. On 22 squares that is $2,200 to $4,400 for one layer. Many building codes allow a second layer of shingles over the first, which saves that money, but most roofers advise against it: the old shingles hide soft decking, the extra weight stresses the structure, and some manufacturers reduce the warranty on overlays. If your house already has two layers, a full tear-off is usually required.
Tear-off is also when decking problems show up. Replacing a sheet of rotten plywood or OSB costs $70 to $120. Keep about 10 percent of the budget aside for it.
Step 5: the shape of the roof
A simple gable roof has two flat planes and is the cheapest to cover. Hips, valleys, dormers, skylights and chimneys all add cuts, flashing and waste. As a rule of thumb, a roof with a few hips and valleys costs about 10 percent more per square than a plain gable, and a complex roof with dormers and several skylights about 25 percent more. Waste rises too: order about 10 percent extra shingles for a simple roof and 15 percent for a complex one.
Putting it together: a worked example
A single-story ranch house with a 2,000 square foot footprint, a 6/12 pitch, a few hips and valleys, one old layer and architectural shingles:
- Roof area: 2,000 x 1.10 x 1.118 = 2,460 sq ft, or 24.6 squares.
- Shingles: 24.6 squares x 3 bundles x 1.10 waste = 82 bundles.
- Installed shingles: 2,460 x $4.75 to $7.50 x 1.10 for the shape = $12,850 to $20,300.
- Tear-off: 2,460 x $1 to $2 = $2,460 to $4,920.
- Total: about $15,300 to $25,200, plus permits and any decking.
How to compare quotes
Get two or three quotes and ask each roofer to price the same scope, in writing:
- The number of squares and the exact shingle product line.
- Full tear-off down to the decking, and the price per sheet for replacement decking.
- Synthetic underlayment, plus ice and water shield in the valleys and along the eaves.
- New drip edge, pipe boots and flashing around chimneys and walls.
- Ventilation: ridge vent and intake vents, which most shingle warranties require.
- The permit, cleanup, magnetic nail sweep and the workmanship warranty.
A quote far below the others is usually missing one of these. Contractors certified by the shingle manufacturer can register extended warranties that cover labor as well as materials, which is worth asking about.
When to replace and when to repair
A roof with a few missing shingles or one leak around a vent can often be repaired for a few hundred dollars. Replacement makes sense when the shingles are curling or losing granules across the whole roof, when there are leaks in several places, when the decking feels soft underfoot, or when an asphalt roof is past about 20 years. A roofer's inspection will tell you which one you are looking at.
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