Roof Replacement Cost Calculator
| Material | Installed $/sq ft | 1,800 sq ft total | Lifespan |
|---|---|---|---|
| Asphalt 3-tab | $3.50-5.50 | $6,300-9,900 | 15-20 yrs |
| Architectural shingle | $4.50-7.50 | $8,100-13,500 | 25-30 yrs |
| Cedar shake | $7-12 | $12,600-21,600 | 20-35 yrs |
| Standing-seam metal | $9-16 | $16,200-28,800 | 40-70 yrs |
| Slate or tile | $15-30 | $27,000-54,000 | 75-100+ yrs |
Roof replacement pricing starts with two multipliers everybody underestimates: the roof is 30-50 percent bigger than the floor plan it covers (pitch adds area), and the material row you pick is a 20-to-100-year decision, not a paint color. Installed rates per square foot - tear-off of one old layer included - run $3.50-5.50 for 3-tab asphalt, $4.50-7.50 for architectural shingle, $7-12 for cedar, $9-16 for standing-seam metal and $15-30 for slate or tile.
A typical 1,800 square foot roof therefore lands anywhere from $6,300 in basic 3-tab to $54,000 in slate, which is why the calculator below makes you pick a row and a story count before it shows a number. Two-story access adds roughly 12 percent, steep pitches over 6/12 add their own surcharge, and second tear-off layers add $1-2 per square foot - the line items that separate a fair quote from a hopeful one.
The row you pick is also an energy decision. Cool-roof versions of architectural shingle - not just bare metal - now carry EPA-recognized reflectivity that cuts summer cooling loads in sun-belt states, while snow-country roofs care more about ice-and-water shield at the eaves than about any coefficient. The same roof is a different product in Phoenix and in Buffalo, and the honest quote respects that.
How to use
- Estimate roof area as footprint times 1.3 to 1.5 for pitch - or read the square footage off your last roofing quote and adjust from there.
- Pick the material row that fits the house and the decade you plan to keep it: architectural is the American default for a reason, metal wins the 30-year math, slate wins the forever house.
- Set the story count: two-story access costs about 12 percent more in staging and safety time.
- Use the result as the fair band - a quote above the high end needs a line-item explanation (pitch, tear-off layers, flashing hours), not just a smile.
Frequently asked questions
How much does it cost to replace a 1,800 sq ft roof?
At 2025 installed rates: $6,300-9,900 in 3-tab asphalt, $8,100-13,500 in architectural shingle, $16,200-28,800 in standing-seam metal, and up to $54,000 in slate. The band already includes one tear-off layer and standard flashing; second shingle layers add $1-2 per square foot, and two-story access adds about 12 percent. Any quote dramatically under the band is missing a line item you will meet again later.
Is architectural shingle worth the extra cost over 3-tab?
For almost every roof that has to survive weather, yes: architectural shingle costs about 30-40 percent more up front but lasts 25-30 years against 3-tab's 15-20, carries a better wind rating, and - the underrated part - looks like the roof a buyer expects, which shows up directly in appraisal conversation. The crossover lands around year 12-15, and the second replacement you never have to schedule pays the rest.
How long does each roofing material last?
Plan on 15-20 years for 3-tab, 25-30 for architectural, 20-35 for cedar (with real maintenance), 40-70 for standing-seam metal and 75-100-plus for slate - the material you buy is a decision about which decade you are pricing. Ventilation and underlayment quality move every row: a great shingle over a badly vented attic ages twice as fast, which is why the attic work belongs in the roofing quote, not after it.
Can a roof be replaced in winter?
Yes - asphalt crews install all winter in snow country with warmed shingle storage and hand-sealed laps, and the snow-country ice-and-water shield at the eaves is already part of the spec there. The real winter caveats are caulk-dependent accessories and the day the temperature drops below the sealant window, which is scheduling, not physics. Summer pricing is calmer and fall books out - which makes early winter the quiet season for fair quotes in most markets.
What adds cost beyond the per-square-foot rate?
Five usual suspects: steep pitch above 6/12 and difficult access; tear-off of a second layer; skylights, chimneys and valleys where hand-flashing hours hide; decking rot discovered after tear-off (priced per sheet); and structural upgrades for heavy slate or tile. The calculator bakes in the first two for a two-story selection - the rest belong on the written quote, which is exactly why the fair band matters before you see one.