Roof Replacement Cost Calculator
Estimated cost to replace a roof from its area, material and labour rates.
Result appears here
Fill in the fields and press Calculate.
Formula, calculation, assumptions and sources
Squares = Roof surface area (ft²) ÷ 100
Cost = Squares × (installed rate + tear-off rate) × (1 + uplift%) + fixed fees
Run the calculation to see each step with your own numbers.
2,400 ft² roof, $450/square installed, $75/square tear-off, 10% steep-slope, $500 permit + dumpster.
Squares = 24
Rate = $450 + $75 = $525/square
24 × $525 × 1.10 + $500 = $14,360
- Every rate is exactly what you enter — BuildFactor embeds no market pricing.
- Roof surface area is the sloped area, not the footprint.
- One roofing system across the whole roof. Mixed materials need separate runs.
- Excludes structural repairs (rotten deck, rafters), skylights, chimney work and interior repairs — quote those separately.
- What's a typical per-square rate?
- It varies too much to publish responsibly — asphalt shingle replacement commonly runs a wide range by region, roof complexity and access. Get two or three local quotes and enter the rate they give you.
- Should I include tear-off?
- Yes if the old roof is being removed (usually the case, and often required by code for a third layer). Enter 0 only for a permitted layover.
Roofing square
1 square = 100 ft² of roof (NRCA convention).
Rates
User-supplied. BuildFactor intentionally embeds no market price — you enter your own quoted rates.
About the Roof Replacement Cost Calculator
The Roof Replacement Cost Calculator estimates what a re-roof will cost from the roof area and per-square rates for tear-off, materials and labour that you enter from your own quotes — it carries no regional pricing. It returns a cost range, not a fixed bid. For a metal roof specifically, use the Metal Roof Cost Calculator.
What you enter
- Roof surface area — Sloped area, not footprint — from the Roof Area Calculator.
- Installed rate per square — Your quoted price to supply + install one square (100 ft²) of the new roof.
- Tear-off rate per square — Cost to remove + dispose of the old roof, per square. 0 for a layover.
- Steep-slope / complexity uplift — Add a percentage for a steep or cut-up roof (hips, valleys, dormers). 0 for a simple walkable gable.
- Fixed fees — Permits, dumpster, access equipment — a flat amount.
What you get back
- Estimated replacement cost — An estimate from the rates you entered — get firm quotes before you commit.
- Roofing squares — the exact result of the calculation.
The formula, a worked example, the assumptions behind it and the sources are shown in full below the calculator.
Related calculators
- Roof Area Calculator — Sloped surface area of a simple gable or hip roof from its footprint and pitch.
- Roof Shingle Calculator — Shingle bundles and roofing squares for a roof of a given surface area.
- Metal Roof Cost Calculator — Estimated cost of a metal roof from its area, panel type and installed rates.
- Roof Pitch Calculator — Roof angle, slope factor and rise-in-12 pitch from a rise and run.
Part of the Roofing calculators.