Roof replacement cost by house size
Estimates from this page's default prices for architectural shingles on a simple gable roof at 6/12 pitch, tearing off one old layer. Roofers price by the square: 100 sq ft of roof surface. Change the defaults above to match quotes near you.
| House | Roof (1 story) | 1 story | 2 stories |
|---|---|---|---|
| 1,000 sq ft | 12.7 squares | $6,700–$10,100 | — |
| 1,500 sq ft | 18.6 squares | $9,700–$14,550 | $5,500–$8,300 |
| 2,000 sq ft | 24.4 squares | $13,000–$19,500 | $7,100–$10,650 |
| 2,500 sq ft | 30.3 squares | $15,900–$23,900 | $8,700–$13,050 |
A 2-story house has a smaller roof than a 1-story house with the same floor area, because the roof only covers the footprint. The 2-story column has less roof but costs a little more per square for the extra height.
How much does it cost to replace a roof on a 1,500 sq ft house?
A 1,500 sq ft, 1-story house has about 1,858 sq ft of roof at 6/12 pitch in this model, or 18.6 squares. In architectural shingles with one layer torn off, that comes to about $9,700–$14,550, or about $652 per square ($6.52 per sq ft of roof). In 3-tab shingles it's about $9,000–$13,450.
The same house with two stories has only about 9.7 squares of roof, and comes to about $5,500–$8,300.
What a replacement roof costs on your house
Roof size, pitch and shape swing the price more than anything else, so start from your own house above. On the 1,500 sq ft example, a hip roof brings it to about $10,450–$15,650, and a cut-up roof with dormers and valleys to about $11,450–$17,200. A steep 10/12 pitch brings it to about $13,250–$19,850. Tearing off two layers instead of one comes to about $11,400–$17,100.
Flat roof replacement cost
Flat and low-slope roofs take a membrane instead of shingles. Choose TPO or modified bitumen above. Our defaults are $250 per square for TPO and $220 for modified bitumen in materials, including the cover board, fasteners or adhesive and flashing, and $410 per square for install labor. A 1,000 sq ft 1-story footprint comes to about $7,900–$11,850 in TPO and $7,500–$11,300 in modified bitumen. A 1,500 sq ft footprint in TPO comes to about $11,400–$17,100, or about $8.57 per sq ft of roof.
What changes the price
- Roof area: footprint, overhang and pitch set the squares. A steeper roof has more surface over the same house.
- Pitch: above 6/12, crews work slower and need more safety gear. Labor rises 15–50% here.
- Shape: hips, valleys and dormers add waste and labor.
- Tear-off: each old layer adds labor and dumpster weight.
- Rotten decking: often unknown until the old roof is off. Many roofers quote a price per sheet in advance.
- Permits: many towns require a permit for a re-roof. Enter the fee above.
How this estimate works
The footprint is floor area ÷ stories, treated as a rectangle 1.5 times as long as wide, plus a 1 ft overhang all round. Roof area is that times the pitch factor √(1 + (pitch ÷ 12)²), as in our roofing calculator. Waste is 10% on a gable roof, 15% on a hip and 20% on a cut-up roof.
Materials per square are 3 bundles of architectural shingles at $45 ($135), or 3-tab at $38 ($114), plus $45 per square for underlayment, ice and water shield, drip edge, starter, ridge cap and nails, from the roofing calculator's defaults. Contractor markup on materials is 20%. Labor is priced per square the way roofers bill it, at a billed rate that includes the contractor's overhead and profit, not a crew wage: $300 per square to install shingles ($280 for 3-tab, $410 for flat membranes) plus $90 per square for each layer torn off. That is multiplied by 1.15–1.5 for steep pitches, 1.1 for 2 stories (1.2 for 3) and 1.1–1.25 for hips or cut-up roofs. Tear-off weighs about 250 lb per square per layer, hauled in 3-ton dumpsters at $450. The range is the result minus 20% to plus 20%. Change any of these above.
Homewyse puts a composition (laminated) shingle roof at $6.20–$8.02 per sq ft installed (Homewyse, May 2026, tear-off listed as an option). This estimate's default comes to about $6.52 per sq ft of roof, including tear-off of one layer. Homewyse puts a membrane roofing system at $8.04–$10.29 per sq ft (Homewyse, May 2026). Our TPO default comes to about $8.57.
Getting quotes
Ask each roofer for the number of squares, the shingle line, the underlayment, how many layers come off, the price per sheet of decking, and who pulls the permit. If one is far below this estimate, ask what's left out.
Questions
How much does it cost to replace a roof on a 1,500 sq ft house?
With this page's defaults, a 1,500 sq ft 1-story house at 6/12 pitch has about 18.6 squares of roof and comes to about $9,700–$14,550 in architectural shingles with one layer torn off. A 2-story house of the same size comes to about $5,500–$8,300.
How much does a roof cost per square?
About $652 per square installed for architectural shingles on the 1,500 sq ft example with these defaults. Steep pitches, cut-up roofs and extra layers raise it.
How much does a flat roof replacement cost?
With our defaults, a 1,000 sq ft flat roof comes to about $7,900–$11,850 in TPO and $7,500–$11,300 in modified bitumen, with one old layer torn off.
How many squares is a 2,000 sq ft house?
In this model, a 2,000 sq ft 1-story house at 6/12 pitch has about 24.4 squares of roof. As 2 stories, it has about 12.7 squares.