sq ft
The area the roof covers seen from above. A two-story house has the same footprint as its ground floor.
/12
Old layers to tear off
%
More for hips, valleys and dormers. Use what your own jobs run.
ft
Leave at 0 to estimate from the footprint.
ft
Leave at 0 to estimate from the footprint.
Adjusts labor to your state's wages.
Roof replacement cost
$8,550 to $19,000
Typical $13,775 for 20.9 squares of architectural asphalt
1,901 sq ftRoof area
20.9Squares
63Bundles
Free. Opens Koira in a new tab, where your numbers become an estimate you can send.

How we got this

  1. Pitch multiplier√(1 + (6 ÷ 12)²) = 1.118A sloped roof has more area than the ground it covers. The table below shows each pitch.
  2. Roof area1,700 sq ft × 1.118 = 1,901 sq ft
  3. Squares with waste1,901 × (1 + 10%) ÷ 100 = 20.9 squaresA square is 100 sq ft of roof.
  4. Installed rateArchitectural asphalt: $3.75 to $6.75 per sq ft, typical $5.25From Today's Homeowner ($350 to $750 a square) and HomeAdvisor. Low is the average of the sources' lows, high the average of their highs, typical the middle of the two. Priced on roof area before waste; the installed rate already carries the roofer's waste.
  5. Tear-off1 × $0.75 to $3.25 per sq ftFixr ($50 a square on average and up to $150, dumping included) and Today's Homeowner ($1 to $5 a sq ft). A second layer is priced the same as the first; that is our assumption, not a guide figure.
  6. Labor adjusted for the US average×1, national prices. Add your ZIP to adjust labor to your state.Labor share is the average of Bob Vila (about 60%), Fixr (40% to 60%) and This Old House (65%).
  7. Total$8,550 to $19,000, typical $13,775
  8. Shingle bundles20.9 squares × 3 = 63 bundlesThree bundles to a square for standard 3-tab and architectural shingles (ServiceTitan). Some premium lines pack 4; check the wrapper.
  9. Starter168 ft ÷ 116 ft = 2 bundlesCertainTeed SwiftStart covers 116 ft a bundle. Run it along eaves and rakes.
  10. Underlayment2,091 sq ft ÷ 432 = 5 rolls of #15 felt (10 of #30)ServiceTitan: #15 felt covers about 432 sq ft a roll, #30 about 216 sq ft. Synthetic rolls cover more; use the maker's figure.
  11. Edges and ridge168 ft of drip edge, 50 ft of ridge capEstimated from the footprint as a 1.5 to 1 rectangle. Measure them for an order.
PitchMultiplierRoof area for your footprint
1/121.0031,706 sq ft
2/121.0141,723 sq ft
3/121.0311,752 sq ft
4/121.0541,792 sq ft
5/121.0831,842 sq ft
6/121.1181,901 sq ft
7/121.1581,968 sq ft
8/121.2022,043 sq ft
9/121.2502,125 sq ft
10/121.3022,213 sq ft
11/121.3572,306 sq ft
12/121.4142,404 sq ft

Sources: Today's Homeowner, asphalt roofing cost; Today's Homeowner, metal roof cost; HomeAdvisor, roof installation cost; Fixr, roof replacement cost; Bob Vila, roof replacement cost; This Old House, new roof cost; ServiceTitan, roofing calculators (bundles and felt coverage); CertainTeed SwiftStart starter (coverage per bundle); Roof pitch multiplier table; BLS Occupational Employment and Wage Statistics, May 2025 (state and national files); US Census Bureau, 2020 ZIP Code Tabulation Area to county relationship file. Checked 2026-10-08.

Roof replacement cost calculator by Koira