Does the tool know how many decking sheets are damaged?

No. You enter known or assumed whole sheets. Inspection and the contractor’s repair scope determine actual work; the calculator cannot observe hidden conditions.

How does it handle two roofing layers?

It multiplies measured roofing squares by two and by your per-square, per-layer removal rate. Disposal remains a single project allowance unless you edit it.

Can I enter zero layers for an overlay?

Zero excludes removal cost mathematically. It does not determine whether an overlay is appropriate or permitted for your roof, product or local requirements.

Where do steepness and access costs go?

Use the labor rate quoted for the actual roof and add separately quoted work in the appropriate allowance. Do not add another complexity charge when it is already included.

Can I reuse the new-roof cost plan?

Saved roof area can be imported explicitly. Each budget calculator keeps its own rates and saved plan so a replacement scenario does not silently overwrite the new-installation scenario.

Replacement scope and budget

Roof Replacement Calculator

Estimate a roof replacement budget using your installation rates, removal layers, disposal, deck repairs and additional work. See each allowance and export your plan.

Removal priced by layer
Explicit decking allowance
Saved inputs and CSV report

Editable US-dollar planning budget

Plan a roof replacement budget

Save to this browser

Starting rates are examples, not local market prices. Replace them with itemized quotes. Each cost should appear once; enter zero for costs already included elsewhere.

Material pricing method

Roof and materials

Measured sloped roof areasq ftUse measured roof surface, before waste. Do not enter floor area.Material allowance%Applies only to area-priced materials, never to labor or tear-off.Material rate per order sq ft$/sq ftExample only. Replace with your supplier rate; define what it includes.

Installation and allowances

Installation labor per roof sq ft$/sq ftExample only. Use a labor-only rate; do not re-enter a bundled installed quote.Accessories not already included$Trim, flashing or system components excluded from the material rate/quote.Delivery / equipment allowance$Use the quoted amount. Set to zero if included elsewhere.Permit allowance$User-entered allowance, not a local fee lookup.Tax allowance$Enter supplier/contractor tax in dollars. This tool does not determine taxable items or local tax law.

Removal and repairs

Layers to removelayersWhole layers. Zero excludes tear-off; it does not establish that an overlay is permitted.Removal per square per layer$/sqExample rate per 100 sq ft per layer. Keep disposal separate unless already included.Disposal allowance$Enter once for the project. Use zero if included in removal pricing.Deck sheets to replacesheetsKnown or assumed whole-sheet count. Not inferred from roof age or area.Installed cost per deck sheet$/sheetExample allowance including sheet and repair labor; avoid counting this labor again.Other replacement-only work$Ventilation, flashing or other quoted work not included in the other lines.

Reserve

Contingency reserve%Added to the entire entered subtotal, including tax and fees. Not a price forecast.

Planning budget with reserve

$13,816.00

Based on your entries, not a contractor quote or a market-price prediction.

Your itemized estimate

Roofing materials: $3,960.00; Area × (1 + material allowance / 100) × material rate.
Installation labor: $5,400.00; Measured area × labor rate, without material waste.
Additional accessories: $500.00; User-entered amount excluded from material pricing.
Delivery / equipment: $200.00; User-entered project allowance.
Permits: $150.00; User-entered project allowance.
Tax allowance: $0.00; Entered dollars; no tax rules assumed.
Tear-off: $1,350.00; Measured squares × layers × removal rate per square per layer.
Disposal: $500.00; Added once; set to zero if included in removal.
Deck repair: $500.00; Whole sheets × installed repair rate.
Other replacement work: $0.00; User-entered work not counted in other lines.
Subtotal before reserve: $12,560.00; Sum of displayed line items, each rounded to cents.
Contingency reserve: $1,256.00; Entered percentage of the entire subtotal.
Budget per measured sq ft: $7.68 / sq ft; Includes all entered allowances and reserve.

A reserve is an amount you choose to hold aside, not a guaranteed high-price bound. Hidden damage, local requirements, access and quote scope can change the actual total.

Transparent

Formula, intermediate values and rounding rules are visible.

Private by default

Saved project measurements stay in this browser unless you copy a share link.

Purchase-aware

Inputs, units and limitations stay visible so you can verify each estimate.

Separate replacement work from new-roof installation

A replacement budget includes the new roof system plus the work required to remove or prepare the existing roof. This calculator starts with materials and installation labor, then adds tear-off, disposal, a chosen deck-repair quantity and other replacement-only work. Every starting dollar rate is an example, not a current market quote.

Tear-off uses measured roof area divided by 100 to get roofing squares, multiplied by the number of layers and the removal rate per square per layer. This calculation does not multiply by new-material waste. Disposal is entered once for the project; set it to zero if the removal quote already includes it.

Deck repair is an explicit number of whole sheets times the entered installed repair cost per sheet. It is not inferred from roof age or area. Ask the contractor to state the repair unit price and how newly discovered damage will be approved. More complicated framing repairs require their own scope rather than a guessed sheet allowance.

Complexity is represented through your actual quoted labor and extra-work allowances, not a universal steepness multiplier. Add tax and permits as quoted dollars. A contingency reserve is applied once after the itemized subtotal; it is not a guarantee that hidden conditions will fit within the budget.

Tear-off

area ÷ 100 × layers × rate

Rate is dollars per roofing square per layer, before any included disposal adjustment.

Deck repair

whole sheets × installed sheet cost

Use known or explicitly assumed quantities and avoid duplicating repair labor.

Replacement budget

all line items + contingency

Includes installation, removal, repair, allowances and one reserve.

How to use this calculator

1Measure sloped roof area and obtain itemized installation pricing.
2Enter the known number of removal layers and the removal rate’s exact unit.
3Include disposal once and enter a documented or assumed whole-sheet repair allowance.
4Add replacement-only work excluded from other lines, then review permits, tax and reserve.
5Save and export the breakdown; compare it with contractor quotes that cover the same work.

Common mistakes

• Charging removal on waste-adjusted material area.
• Multiplying a whole-project disposal allowance by the number of layers.
• Counting installed deck-repair labor in both the repair and general labor lines.
• Assuming zero removal layers confirms an overlay is allowed.
• Presenting a guessed decking quantity as inspected damage.

Use this calculator when

You want to itemize replacement-specific costs and test repair assumptions.
You have contractor rates or need a clearly labeled example budget to discuss.

Use another method when

You need a diagnosis of hidden damage, structural repair design or a determination that reroofing over existing layers is permitted.
You need insurance coverage, settlement or financing calculations.

Worked example

Replacement with one removal layer and five repair sheets

Start with the $10,210 example installation subtotal. A 1,800 sq ft roof has 18 squares: one layer at $75 per square adds $1,350. Disposal adds $500, and five deck sheets at $100 installed each add $500. The replacement subtotal becomes $12,560.

$12,560 subtotal + $1,256 reserve (10%) = $13,816 planning budget