Roof Replacement Cost Estimator

How this estimator works (and how to check it)

The estimate is three numbers multiplied together, all of them visible in the result panel. First, a national installed-cost range per square for your material: what real jobs cost per 100 square feet including labor, tear-off, disposal, and standard accessories. Second, a state multiplier, because a crew day in Massachusetts does not cost what a crew day in Mississippi costs. Third, difficulty adders that reflect real labor: +10 percent for steep, +20 percent for very steep, +8 percent for a second story, +10 percent for an extra tear-off layer.

None of it is hidden. If your roof is 22 squares of architectural shingle in North Carolina, you can multiply the base range by 22, then by 0.95, and land on the same numbers this page shows. An estimate you can reproduce by hand is an estimate you can trust as a starting point.

What actually drives the price of a roof

• Size, obviously, but per-square cost is not flat. Small roofs cost more per square because setup, delivery, and dumpster costs spread over fewer squares. Do not expect a 10 square roof to cost half of a 20 square bid.
• Material choice sets the tier. Architectural shingle is the value baseline. Standing seam metal and tile are premium systems with different substrates, fasteners, and skill requirements, not just prettier surfaces.
• Pitch and stories are labor multipliers. On a 10/12, everything moves slower and needs staging and harness work. On a two-story, every bundle rides a longer ladder and every tarp run takes twice the care.
• Tear-off layers. A second layer means more labor, more disposal weight, and more dumpster. It also usually means the deck has been cooking under two roofs; budget emotionally for some plywood.
• The stuff no calculator can see. Rotten decking, chimneys that need reflashing, skylights at end of life, code-required ice and water shield, permit costs. This is why the output is a range and why the final bid follows an actual inspection.

How to use the range against real bids

Get your range here, then collect two or three local bids. A bid near or inside your range: normal. A bid far below the bottom: ask what got left out (thin underlayment, no permit, no drip edge, subcontracted labor with no insurance). A bid far above the top: ask what you are paying extra for. Sometimes there is a legitimate answer, like extensive decking replacement or premium warranty coverage. The point of the range is not to catch anyone; it is to force the conversation into specifics.

When insurance is involved

If a storm did the damage, the math changes completely: your out-of-pocket is the deductible, and the negotiation is between your contractor and the carrier. Before you file anything, run the insurance claim readiness quiz to see whether the claim is worth making, because a claim filed carelessly can cost you more than a roof.