How do I calculate the cost of a new roof?

Multiply your home’s footprint by the pitch multiplier to get the roof area, multiply that by the installed price per square foot for your material, then add tear-off. For asphalt shingles that works out to about $4.25 to $9.25 per square foot of roof with one old layer removed, so a 2,000 sq ft roof lands around $8,500 to $18,500.

How accurate is the roof cost calculator?

It gives a budgeting range, not a quote. It accounts for size, pitch, material, tear-off, and complexity, but not your region’s labor rates, rotten decking, permits, or a specific contractor’s pricing. A roofer measuring your roof is the only way to get a firm number, and free roof estimates through Roof Restore Buddy cost nothing.

What is a roofing square?

A square is 100 square feet of roof surface, the unit roofers use to price and order materials. A 2,400 sq ft roof is 24 squares. Standard asphalt shingles usually come three bundles to a square.

How do I find my roof pitch without climbing on the roof?

Measure from the attic. Hold a level horizontally with one end touching the underside of a rafter, mark 12 inches along the level, and measure straight up from that mark to the rafter. That number is the rise, so 6 inches means a 6:12 pitch. Never walk on the roof to measure it.

How much waste should I add when measuring a roof?

Add about 10% to 15% when you are ordering shingles. Waste comes from cuts at hips, valleys, edges, and around vents, so a roof with more of those needs the higher figure. You do not need to add waste to the calculator, because roofers build their waste into the installed price per square foot they quote.

How much does it cost to replace a roof on a 2,000 sq ft house?

A one-story 2,000 sq ft house with a medium pitch has about 2,360 sq ft of roof, which comes to roughly $10,000 to $21,800 with asphalt shingles and one layer torn off. A two-story house with the same floor area has about half the roof, so roughly $5,000 to $10,900. See roof replacement cost by home size for the full table.

Will roofing prices go up in 2026?

Material prices have been rising this year. The Bureau of Labor Statistics producer price index for asphalt shingle and coating materials manufacturing was about 4.7% higher in August 2026 than a year earlier (preliminary data). Labor costs and local demand move prices too, so once you have a quote you like, ask how long the price is held.

Roof Replacement Cost Calculator (2026)

Roof replacement cost calculator

Roof replacement cost is your roof area times the installed price per square foot, plus tear-off. Asphalt shingle roofs usually come to about $4.25 to $9.25 per square foot of roof with one old layer removed. Enter your home’s footprint, pitch, and material below for an instant 2026 estimate, then compare real quotes from local roofers.

How to measure your roof

To measure a roof, multiply your home’s footprint by the pitch multiplier for its slope, then divide by 100 to get roofing squares. You can do all of it from the ground and the attic.

Measure the footprint. Multiply the length and width of the outside walls. Split an L-shaped or T-shaped house into rectangles and add them up, and include an attached garage or covered porch that sits under the same roof.
Find the pitch. Pitch is how many inches the roof rises for every 12 inches of horizontal run. In the attic, hold a level horizontally with one end touching the underside of a rafter, mark 12 inches along the level, and measure straight up from the mark to the rafter. A 6-inch rise is a 6:12 pitch.
Apply the pitch multiplier. Multiply the footprint by the multiplier in the table below to get the sloped roof area.
Convert to squares. Divide the roof area by 100. Roofers price and order by the square.
Add waste if you are ordering material. Shingle maker IKO’s estimating guide puts waste at roughly 10% to 15% of the roof. Standard shingles come about three bundles to a square.

Example: a 40 × 45 ft house has an 1,800 sq ft footprint. At a 6:12 pitch, 1,800 × 1.118 = 2,012 sq ft of roof, or about 20 squares. Ordering with 10% waste means about 22 squares, or 67 bundles of standard shingles.

Roof pitch multiplier table

The pitch multiplier turns flat footprint area into sloped roof area, and it equals the square root of 1 + (rise ÷ 12)². When every plane has the same pitch, a hip roof and a gable roof over the same footprint have the same area, so one multiplier works for both.

Pitch	Angle	Multiplier	Roof area on a 1,500 sq ft footprint
3:12	14.0°	1.031	1,546 sq ft
4:12	18.4°	1.054	1,581 sq ft
5:12	22.6°	1.083	1,625 sq ft
6:12	26.6°	1.118	1,677 sq ft
7:12	30.3°	1.158	1,737 sq ft
8:12	33.7°	1.202	1,803 sq ft
9:12	36.9°	1.250	1,875 sq ft
10:12	39.8°	1.302	1,953 sq ft
12:12	45.0°	1.414	2,121 sq ft

The calculator’s four pitch settings use slightly higher factors (1.08, 1.18, 1.32 and 1.45) to allow for eave and rake overhangs, which add roof area beyond the walls.

Roof replacement cost by size

With asphalt shingles and one old layer removed, a 2,000 sq ft roof costs about $8,500 to $18,500, and every extra 500 sq ft adds roughly $2,100 to $4,600. These are the calculator’s own numbers for a simple roof:

Roof area	Squares	3-tab shingles	Architectural shingles	Metal
1,000 sq ft	10	$4,300–$6,300	$5,300–$9,300	$8,300–$19,300
1,500 sq ft	15	$6,400–$9,400	$7,900–$13,900	$12,400–$28,900
2,000 sq ft	20	$8,500–$12,500	$10,500–$18,500	$16,500–$38,500
2,500 sq ft	25	$10,600–$15,600	$13,100–$23,100	$20,600–$48,100
3,000 sq ft	30	$12,800–$18,800	$15,800–$27,800	$24,800–$57,800

Includes removing one layer of old shingles. Roof area, not floor area: see roof replacement cost by home size and material to convert. For more detail by material, see the asphalt shingle roof cost guide, metal roof cost guide, tile roof cost guide and flat roof cost guide.

What the estimate includes and excludes

The calculator prices a standard full replacement: the new roof covering installed over your existing deck, with the old roof removed.

Included:

Roof area from your footprint and pitch, with a small overhang allowance.
Installed material and labor at published 2026 per-square-foot prices for the material you pick.
Tear-off and disposal of up to two old layers, at $1.25 per sq ft per layer.
About 12% extra for complex roofs with skylights, several valleys, or dormers.

Not included:

Replacing rotten or damaged decking, which a roofer can only see once the old roof is off.
Permits, which usually cost $100 to $500 and more in some cities.
Gutters, skylight replacement, chimney rebuilding, and ventilation upgrades.
Your local labor rates. Prices run higher in high-cost metros; see typical ranges by state.

From ballpark to a real price

Use the calculator to set a budget, then get a firm number from roofers who measure your actual roof. If only part of the roof is damaged, a repair may be enough: see what a roof repair costs. Compare at least three written, itemized estimates for the same scope. Our free roof estimate page shows what a good estimate includes, and if the number is more than you can pay at once, see roof financing options or roof replacement assistance programs.

How we estimate these costs

The per-square-foot rates come from published 2026 industry cost data and typical contractor pricing, cross-checked across several national cost surveys and reviewed in October 2026. Pitch multipliers are straight geometry. Measuring and waste guidance follows shingle manufacturer IKO’s estimating guide. The 2026 price trend uses the Bureau of Labor Statistics producer price index for asphalt shingle and coating materials. Results are rounded to the nearest $100 and are estimates, not quotes.