Roofing Cost Calculator
This roofing cost calculator estimates the cost of a new roof from the building footprint, the roof pitch, your local installed cost per square, and the tear-off cost. Enter the numbers and the roofing cost calculator returns the total cost, the roof area, and the roofing squares to order, so you can check a roof replacement estimate.
Results
The Roofing Cost Calculator is part of our Materials Estimating collection. Browse more materials estimating to size, convert, and check your work alongside this tool.
What the roofing cost calculator shows
Roofing is priced by the square, which is 100 square feet of roof surface. The roofing cost calculator turns the building footprint into the true sloped roof area using the pitch, adds waste, converts to squares, and multiplies by your installed cost per square plus the cost of removing the old roof. Because rates vary so much by region and material, the tool uses the rates you enter rather than averages.
Roof estimate formula
The pitch factor scales the flat footprint up to the sloped surface. Overhangs add a little more; include them in the length and width for accuracy.
Roofing cost calculator example
A 12 m by 8 m building with a 6/12 pitch, an installed cost of 450 per square, tear-off at 100 per square, and 10 percent waste:
That is 13 squares to order. The rates here are examples only.
How to use the roof replacement cost calculator
Enter the building length and width, the roof pitch as inches of rise per 12 inches of run, your installed cost per square, the tear-off cost per square, and a waste allowance. The roof replacement cost calculator returns the total cost, the roof area, the squares with waste, the squares to order, and the pitch factor. Get the cost per square from local roofer quotes for the material you want, such as asphalt shingles or metal.
Reading the roofing estimates per square
The total covers removal and installation at the rates you entered. Quotes may add flashing, ventilation, decking repair, permits, and disposal, so ask what each includes. Steeper roofs and complex shapes with valleys and dormers cost more per square to install.
When to estimate roof replacement cost
- Budgeting a reroof with the roofing cost calculator
- Comparing shingle and metal roof cost per square
- Checking a contractor's roof estimate
- Planning a new roof for a garage or extension
Common roofing cost calculator mistakes
- Using the footprint without the pitch factor.
- Using national average prices. Enter local rates.
- Forgetting overhangs.
Tips for accurate results
- Get at least three local quotes.
- Ask what each quote includes.
- Add overhangs to the footprint.
Metal roof cost calculator vs shingles
A metal roof usually costs more per square to install than asphalt shingles but lasts longer, so compare total cost against expected life. Enter the installed price for each option in turn to see the difference on your roof; the same steps make it a metal roof cost estimator, a steel roof cost calculator, or a tin roof cost calculator, since only the rate changes. A reroof is also a good time to improve attic insulation, which the insulation calculator sizes.
Reroof cost calculator: tear-off or overlay
Some codes allow a second layer of shingles over the first, which avoids tear-off cost. Removing the old roof costs more but lets the roofer inspect and repair the deck. Set tear-off to 0 for an overlay estimate.
Roof price calculator reference (this example roof, 12.71 squares)
| Installed cost per square | Tear-off | Total |
|---|---|---|
| 300 | 100 | 5,083.33 |
| 450 | 100 | 6,989.58 |
| 600 | 100 | 8,895.83 |
| 900 | 100 | 12,708.33 |
Example rates only; use local quotes.
Roofing Cost Calculator FAQ
How is roofing priced?
By the square, which is 100 square feet of roof surface, at an installed rate plus tear-off.
How does pitch affect cost?
A steeper pitch adds roof area and makes installation slower, so both quantity and rate rise.
What is not included?
Typically flashing, ventilation, deck repairs, permits, and disposal, unless your quote includes them.
Can I use this for a metal roof?
Yes. Enter the local installed cost per square for metal roofing.