What a new roof actually costs

Last reviewed September 10, 2026 · Rates verified against 2026 contractor and supplier pricing · Methodology

How the calculator works

Almost every roof cost tool online multiplies your square footage by a single dollar figure and calls it an estimate. That is not how a roof gets priced, and it is why those numbers are so often thousands of dollars off. Roofers estimate in squares — one square equals 100 square feet of roof surface — and they build a bid out of separate line items that each scale differently.

This calculator follows the same sequence a professional estimator does:

1. Convert footprint to roof surface. Your ground-floor footprint is not your roof area. A pitched roof is a set of sloped planes, so the true surface is always larger. We apply a pitch multiplier from 1.06 for a low 2:12 slope up to 1.44 for a very steep 11:12 or greater, then add the waste factor that covers cuts at hips, valleys and rakes.
2. Divide into squares. Roof surface divided by 100. Every subsequent rate is applied per square, which is what makes two different quotes comparable.
3. Apply material rates. Each material carries its own low-to-high range per square for the roofing product itself.
4. Apply labor rates, then multipliers. Labor is material-specific — slate demands a different skill set than asphalt — and is then adjusted for pitch and for building height, since a three-story job needs more staging and slows the crew's material handling.
5. Add tear-off by layer. Removal and dumpster disposal runs per square, per existing layer.
6. Add the parts nobody quotes out loud. Underlayment, ice-and-water shield, drip edge, starter strip, ridge cap, step and counter flashing, and ridge or box ventilation. Bundled, these run $60 to $110 per square and are a common place for a cheap bid to cut corners.
7. Add optional scope and permits. Decking replacement, gutters, chimney reflashing, skylight reflashing, and the municipal permit and inspection fee.
8. Apply the regional multiplier to the labor-sensitive portion of the total.

The output is a range rather than a single number, and that is deliberate. Even a careful estimator standing on your roof will give you a range until the old material comes off and the decking is visible. Anyone who gives you a precise figure sight unseen is guessing or planning to revise it later.

The seven things that set your price

1. Material

This is the largest single swing. The same house that costs $12,000 in architectural asphalt can cost $70,000 or more in natural slate. Asphalt dominates the American market for a reason: it is inexpensive, every crew knows how to install it, and a quality architectural shingle lasts 25 to 30 years. Metal costs two to four times as much up front but often outlives two asphalt roofs, which changes the math if you plan to stay put.

2. Roof pitch

Pitch is expressed as rise over a 12-inch run. A 6:12 roof rises six inches for every foot of horizontal travel. Two effects stack here. Geometrically, a steeper plane covers more surface for the same footprint. Practically, once a roof passes roughly 7:12, crews can no longer walk it freely and need roof jacks, staging and fall arrest, which slows everything down. That combination is why moving from moderate to very steep can add 30 to 40 percent to the job.

3. Roof complexity

Two roofs of identical area can differ by thousands. A simple gable — two planes, one ridge — is fast. Add hips, valleys, dormers, turrets, multiple roof levels and skylights and you add cutting, flashing, waste and time. Valleys and flashing details are also where roofs leak, so they demand the crew's most careful work. Our estimate spreads this across the low-to-high range; if your roof is visibly complicated, plan on the upper half.

4. Tear-off and decking condition

Removing old material is real labor and real dumpster weight. A second layer roughly doubles that line. And nobody, including your contractor, knows the condition of the plywood or plank sheathing underneath until it is exposed. Fifteen percent replacement is a reasonable planning assumption; a roof that has been leaking quietly for years can run far higher. Insist that the contract states a per-sheet price for replacement decking in writing before work starts.

5. Where you live

Materials cost roughly the same nationwide. Labor does not. Crew rates, disposal fees, permit costs and insurance requirements vary widely, which is why the same roof can cost 30 percent more in the Northeast than in the South Central states. Local code adds to it: ice-and-water shield requirements in cold climates, wind-uplift and secondary water barrier rules in Florida coastal counties, and fire-rating requirements in parts of California all raise the floor.

6. Season and crew availability

Roofing is seasonal and weather-driven. Late spring through early fall is peak demand and peak pricing. After a regional hail or wind event, local demand can spike for months and prices follow. Booking in the shoulder season, when a good crew has a gap in the schedule, is one of the few genuine discounts available to a homeowner.

7. Warranty and contractor tier

A manufacturer-certified installer offering an extended system warranty costs more than a two-person crew working from a truck. Sometimes that premium is worth it and sometimes it is not, but understand what separates two bids before choosing on price. A workmanship warranty is only as durable as the company standing behind it.

Cost by roofing material

Installed cost per square, materials and labor combined, before tear-off, permits and regional adjustment. These are the same ranges the calculator uses.

Two cautions on the exotic end. Tile and slate are heavy — clay and concrete run 600 to 1,100 pounds per square, slate up to 1,500 — and many homes framed for asphalt need structural reinforcement to carry them, which is a separate expense not included above. And a slate or tile roof is only as good as the installer; the pool of crews who can do it correctly is small in most markets.

Cost by roof size

Architectural asphalt, moderate pitch, single story, one layer torn off, at the national average. Use it as a quick reference point against your own calculation.

Repair or replace?

Replacement is not always the answer, and a contractor who leads with it before inspecting is telling you something. Weigh these:

• Age against expected life. An asphalt roof at 22 of an expected 25 years is not worth a $2,000 repair. The same repair on a 10-year-old roof clearly is.
• Extent. Damage confined to one slope or one flashing detail is a repair. Granule loss, curling and cracking spread across every elevation is systemic.
• Granules in the gutters. Heavy accumulation means the shingle mat is losing its UV protection. That is end-of-life, not a repair item.
• Deck movement. Sponginess underfoot or visible sagging between rafters means moisture has reached the sheathing. Structural, and urgent.
• Daylight in the attic. Go up on a bright day with the lights off. Light through the boards, or dark staining on the underside, tells you more than any curbside inspection.
• Repeat repairs. Three service calls in two years is a roof asking to be replaced.
• Timing. If you are replacing within a couple of years anyway, and a covered storm event just occurred, sequence matters. See our hail damage claim guide.

Tear-off vs. overlay

An overlay — new shingles laid straight over the old — removes the tear-off line item and can save $1,000 to $2,500 on a typical home. It is legal in most jurisdictions up to two total layers. It is also, in the settled view of most roofing professionals and home inspectors, a false economy.

The reasons are consistent. The decking cannot be inspected, so any rot stays hidden and keeps spreading. The doubled layer traps heat, and heat is what ages asphalt, so the new roof reaches end of life measurably sooner. The added weight is carried by framing that was not designed for it. The finished surface telegraphs every irregularity beneath. Many manufacturers reduce or void warranty coverage over an existing layer. And when the overlay does fail, the next homeowner pays to remove two layers at once. If you are selling within a year or two, an overlay may pencil out. If you are staying, tear it off.

How to read a roofing quote

The most useful thing you can do with the number this calculator produces is take it into three conversations with local contractors. A bid you can actually evaluate states, in writing:

• The square count and how it was measured. No square count, no comparison.
• The exact shingle manufacturer, product line and color — not "architectural shingles."
• Underlayment type and exactly where ice-and-water shield goes: eaves, valleys, penetrations, and how many feet up from the eave.
• Flashing: new step and counter flashing at walls and chimneys, or reuse of existing. Reused flashing is the single most common source of a leak in an otherwise new roof.
• The ventilation plan, intake and exhaust. Inadequate ventilation shortens shingle life and can void the warranty.
• A per-sheet price for replacement decking, agreed before the job starts.
• Who pulls the permit and schedules inspection.
• Disposal, dumpster placement and property protection — landscaping, gutters, driveway, magnetic nail sweep.
• Both the manufacturer warranty and the workmanship warranty, with their durations stated separately.
• The payment schedule. A modest deposit is normal. A demand for most of the money before materials are on site is not.

Frequently asked questions

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