How the Roof Replacement Calculator Works
A home's floor or footprint area does not necessarily equal its roof surface area. A pitched roof has more surface area than its horizontal footprint, and eave overhangs can increase that area further.
The calculator estimates roof surface area using the selected pitch, applies the chosen waste allowance and then estimates a cost range based on roofing material.
Roof Pitch
Pitch describes how much a roof rises for every 12 inches of horizontal run. A 6/12 roof rises 6 inches for every 12 inches of run. Steeper roofs have greater surface area and may also require additional labor and safety measures.
Waste Allowance
Roofing materials normally require extra material for cuts, valleys, ridges, starter courses and installation waste. Simple roofs may require less waste than complex roofs with many hips and valleys.
Roofing Squares
Roofing contractors commonly measure roofing in squares. One roofing square represents 100 square feet of roof surface.
Replacement Cost
A real replacement quote can also include removal and disposal of old roofing, underlayment, flashing, permits, decking repairs and other project-specific work.
Calculator estimate vs. contractor quote
Use this calculator to establish a preliminary budget. A roofing contractor can inspect the actual roof, identify hidden damage and provide pricing based on local material and labor costs.
Find Roofers Near YouRoof Replacement Calculator FAQs
How is roof replacement cost estimated?
The calculator estimates roof surface area from the building footprint and roof pitch, adds a waste allowance, and applies an approximate installed cost range for the selected roofing material.
What is a roofing square?
One roofing square equals 100 square feet of roof surface area.
Does house square footage equal roof square footage?
Not usually. Roof pitch, overhangs and roof shape can make the actual roof surface larger than the building footprint.
Is this calculator a contractor quote?
No. It is a preliminary budgeting estimate. Local labor, tear-off requirements, permits, decking repairs and roof complexity can substantially change a real contractor quote.