A new roof typically costs $8,000–$30,000 for an average home, but the range widens with premium materials like metal, tile, or slate. Use this free roof replacement cost calculator to estimate your project cost based on home footprint, pitch, roofing material, number of stories, and how many existing layers need to be torn off. Costs are calculated per roofing square (100 sqft of roof area).
Material is the biggest driver — slate or tile can cost 5–8x what asphalt shingles cost. Pitch matters: steep roofs need safety equipment and slow down installation, raising labor 20–40%. Multi-story homes cost more due to setup, scaffolding, and risk. Tearing off two existing layers (instead of one) roughly doubles the disposal cost. Most roofs use the home footprint × ~1.3 to estimate actual roof surface area.
This roof calculator works in roofing squares — each one equals 100 square feet of roof surface. It first converts your home's footprint into actual roof area by applying a pitch factor: about 1.10 for a low slope, 1.30 for a medium slope, and 1.55 for a steep roof. That area is divided by 100 to get squares, then priced by material at an installed rate per square: roughly $350 for 3-tab asphalt, $525 for architectural shingles, $1,100 for metal, $1,500 for tile, and $2,600 for slate. The tool layers on multipliers for pitch (steep roofs are slower and need fall protection) and stories (more setup and scaffolding), plus a tear-off charge of about $90 per square for one existing layer or $200 for two. A regional factor from about 0.92× to 1.22× finishes the math, and the result is split into material versus labor and tear-off.
Take a 2,000-square-foot footprint, two-story home with a medium-pitch roof getting architectural shingles in the Midwest, with one existing layer to remove. The footprint times the 1.30 medium-pitch factor gives 2,600 square feet of roof, or 26 squares. At $525 per square that's $13,650, nudged up by the medium-pitch (1.10) and two-story (1.10) multipliers to about $16,500, plus tear-off of 26 × $90 = $2,340. The Midwest factor (0.95) trims the total to roughly $17,900 — close to $688 per square installed. Switch to standing-seam metal and the same roof climbs past $33,000, since material is the dominant cost driver in any roof.
A roofing square equals 100 square feet of roof surface — the unit roofers use to price materials and labor. Because a pitched roof has more surface than the home's footprint, contractors multiply the footprint by a pitch factor (roughly 1.1 for low slopes up to about 1.55 for steep ones) to find the actual roof area, then divide by 100 to get squares.
For an average single-family home, architectural asphalt shingles typically run $8,000 to $18,000 installed, while basic 3-tab shingles sit a bit lower. Metal, tile, and slate cost considerably more. Your final price depends on roof size, pitch, number of stories, tear-off layers, and regional labor rates.
Many codes allow a single overlay of new shingles over one existing layer, which saves on tear-off and disposal. However, a complete tear-off lets the roofer inspect the decking, replace damaged underlayment, and start clean — and it's required once two layers already exist or the deck is compromised. Overlays can also trap heat and shorten the new roof's life.
A steeper roof has more surface area for the same footprint, and crews must work more slowly with harnesses, roof jacks, and staging for safety. That combination of extra material and slower, more hazardous labor commonly adds 20 to 40 percent over a comparable low-slope roof.
A note from me: Roofers price by the square and almost always find a surprise or two once the old material comes off, so treat this as a planning estimate rather than a contractor quote. Get a written, measured bid that spells out tear-off, decking repair, and flashing. — Lisa Tran