Estimate a roof replacement from tear-off to cleanup
General contractors and trade contractors preparing a bid or reviewing a completed estimate. Replace the hypothetical inputs with your own costs and contract figures. Results update as you type; use the chart and pinned comparison to examine a revised estimate.
Formula and worked example
Revenue = base contract + approved changes. Direct cost = materials + labor + subcontractors + equipment + permits + other. Total cost = direct cost + overhead + expected contingency expense. Profit = revenue − total cost. Margin = profit ÷ revenue. Target price = total cost ÷ (1 − target margin).
Hypothetical roof replacement: $18,000 revenue less $6,500 materials, $4,000 labor, $500 equipment, $200 permits, $800 other direct costs, $1,500 overhead and $500 expected contingency leaves $4,000 estimated profit, or 22.22% margin. Total cost is $14,000; a 20% target margin needs a $17,500 price. These figures are examples, not local roofing prices.
Define the roof and the replacement scope
Record measured roof area, pitch, access, existing layers, penetrations and the system being installed. A roofing square describes 100 square feet of roof area, but this calculator takes dollar costs, not area. Convert your own measured quantities and quoted unit costs into the material and labor inputs before using the result.
Separate the base replacement from optional work and uncertain decking repairs. Note what is included in underlayment, flashing, ventilation, edge details and cleanup. A quote that excludes a difficult access condition is different from one that prices it. This page helps you evaluate the financial estimate; it does not calculate structural requirements or specify a roofing system.
Build a materials total from quantities
Use supplier quotes for the actual products and quantities: roofing material, underlayment, fasteners, flashing and other included components. Account for waste, delivery and applicable costs in your estimate. Do not assume a universal waste percentage across simple roofs and complex layouts; use the takeoff and the installation conditions.
Place the total in Materials. If a supplier quote includes delivery or tax, avoid adding it again in Other direct job costs. Record the quote's date and assumptions outside the calculator so you know what changed when repricing. A small price increase across a large purchase can consume more profit than a visible item you negotiated carefully.
Include tear-off, disposal and site protection
Plan labor for removing the existing roof as well as installing the new one. Include handling, loading, disposal fees and equipment you expect to use. The default example places $800 in other direct costs as a hypothetical allowance; replace it with your own estimate rather than interpreting it as a standard disposal charge.
Protect landscaping and finished surfaces where your scope requires it, and allow crew time for cleanup. Extra layers or difficult access may change both labor and disposal. Use the Higher disposal cost preset to examine the financial effect of that one allowance increasing. It leaves the contract price fixed so the resulting reduction in profit is visible.
Estimate crew time and weather exposure
Convert expected crew hours into a fully considered labor cost. Include tear-off, installation, setup, protection and cleanup, plus owner production labor if you treat it as a cost. Check whether your crew rate already contains payroll burden and overhead before adding separate allowances. Labor estimates based only on installation time can miss meaningful work.
Weather can change the schedule, but not every extra calendar day has the same cost. Estimate expenses you actually expect, such as additional rental or remobilization. Use expected contingency expense for likely additional spending; keep an unused cash reserve separate. The Extra crew time preset shows how a $1,200 labor increase changes the hypothetical job's profit.
Read the roof's profit and cost-overrun scenario
The default total cost is $14,000 against an $18,000 price, leaving $4,000 profit. At 20% target margin the calculated target price is $17,500. A 10% increase across all modeled costs would add $1,400 and reduce profit to $2,600. The chart is a sensitivity comparison, not a forecast that every expense will rise together.
Pin the first estimate, then revise a particular cost if you want a narrower comparison. Review whether the final price covers your full scope and recovery of business overhead. A strong project margin is still separate from cash availability: a material purchase before customer collection can require funding even when the job is profitable.
Use actual roof jobs to improve the next bid
After each project, compare actual supplier costs, crew hours, equipment and disposal with the bid. The job cost tracker can preserve those totals in this browser and export a report. Review recurring differences such as unpriced extra layers, cleanup hours or return trips. Do not treat invoices that have not arrived as savings.
For added work, agree on the scope and price through your contract's process and document the change. Approved revenue belongs in the change-order input; a customer's possible future request does not. Revisit the estimate after material quantities or crew assumptions change instead of leaving the original target margin as an unsupported promise.
Frequently asked questions
Does this calculate a roofing price per square?
No. It evaluates the revenue and dollar costs you enter. You can divide your final quoted price by the measured roofing squares separately to compare jobs, but that unit price does not explain differences in tear-off, pitch, access, system or scope. Start with a complete takeoff rather than treating another roof's price per square as your estimate.
Where do decking repairs belong?
Include known repairs in the applicable material and labor costs when they are part of the base scope. For uncertain extra work, record the allowance or exclusion clearly and follow your actual change-order process. Do not count hypothetical repair revenue as approved revenue merely to make the original bid look profitable.
What is a good roofing profit margin?
This tool does not prescribe an industry margin. Choose a target based on your complete costs, overhead recovery, capacity, risk and business goals, then compare it with completed work. The default target is hypothetical. A company net margin and a roof's estimated margin after entered costs are different measures.