House Flipping Calculator: Estimate ARV, Rehab Costs, Holding Costs, and Profit

Overview

A fix-and-flip deal should be analyzed as a complete project, not simply as a purchase price plus a repair allowance. The property must be bought, improved, financed, carried, and sold. Each stage adds cost or uncertainty.

The core calculation is:

Projected profit = sale price − total project costs

For a flip, total project costs commonly include:

• Purchase price
• Purchase closing costs and immediate acquisition expenses
• Renovation and construction costs
• Renovation contingency
• Loan interest, points, and other financing charges
• Property taxes, insurance, utilities, maintenance, and other holding costs
• Real estate commissions, seller concessions, staging, and other selling costs

The sale price is usually based on the property’s estimated ARV: the value it may achieve after the planned work is complete. An ARV analysis using relevant comparable sales is more useful than relying on a broad neighborhood average. The finished property should be compared with homes that are similar in location, size, layout, condition, and buyer appeal.

Use the calculator as a decision tool, not a guarantee. A projected profit can change when a contractor revises a quote, a permit delays the schedule, a lender changes terms, or the market requires a lower listing price.

How to estimate

1. Establish a realistic ARV

Begin with the likely finished condition, not the condition you hope to create. Identify the improvements that will be completed, then review comparable renovated properties. Pay attention to the features buyers in that market actually reward, such as bedroom and bathroom count, parking, floor plan, outdoor space, and overall finish level.

Do not automatically add the cost of every upgrade to the value. A renovation may be necessary to compete without increasing value dollar for dollar. For more detail on selecting and pricing comparable sales, see the guide to comparative market analysis for flippers.

2. Build the renovation budget

Turn the property inspection and walkthrough into a line-item scope of work. Separate essential work—such as safety, structural, water-intrusion, electrical, plumbing, or heating concerns—from cosmetic improvements. Obtain contractor bids where possible and use a rehab cost per square foot guide only as an early screening tool.

A useful renovation budget includes materials, labor, delivery, disposal, permits, design or engineering needs, and cleanup. Add a contingency to the renovation subtotal rather than hiding it in a general miscellaneous line. The appropriate allowance depends on the project’s age, complexity, visibility of systems, and quality of the initial inspection. A cosmetic project with a clear scope may require less flexibility than a gut renovation, but neither should be modeled at zero contingency.

3. Calculate financing costs

List the actual terms being considered for the purchase and renovation. Relevant inputs may include loan amount, interest rate, origination points, inspection or draw fees, extension fees, and the portion of the renovation funded by the lender.

For a simple estimate, calculate interest using the expected average loan balance and project duration. If the loan balance changes as draws are made, use a month-by-month schedule instead. Financing costs are often understated when investors calculate interest only on the purchase price or assume the project will finish on the ideal timeline.

4. Add holding and selling costs

Holding costs are the recurring expenses incurred while owning the property. Include taxes, insurance, utilities, lawn or snow care, security, maintenance, loan payments, and any association charges. A monthly holding-cost checklist helps prevent small recurring expenses from disappearing from the analysis.

Selling costs may include brokerage compensation, transfer-related charges, attorney or settlement fees, staging, photography, marketing, buyer credits, and the cost of correcting last-minute inspection items. Use a percentage for costs that scale with the sale price, but list fixed costs separately.

Inputs and assumptions

Keep the calculator editable. A spreadsheet is often sufficient if each assumption has its own cell and formulas are not replaced with typed totals. The following input structure creates a repeatable deal analysis:

• Acquisition: purchase price, purchase closing costs, inspection, appraisal, and immediate repairs.
• ARV: expected sale price, supported by comparable renovated properties.
• Renovation: line-item scope, contractor quotes, owner-supplied labor, materials, permits, and contingency.
• Financing: loan amount, rate, points, fees, draw schedule, and expected months outstanding.
• Holding: monthly taxes, insurance, utilities, maintenance, association charges, and loan-related payments.
• Sale: selling percentage, fixed closing expenses, staging, concessions, and expected time on market.
• Return target: the minimum dollar profit or return requirement that makes the risk acceptable.

Separate known figures from estimates. For example, a signed contractor proposal is a different quality of input from a rough allowance based on square footage. Label each item as quoted, inspected, estimated, or unknown. This makes it easier to see where the deal is most vulnerable.

To estimate maximum allowable offer (MAO), use:

MAO = ARV − selling costs − renovation cost including contingency − holding costs − financing costs − purchase costs − target profit

This formula becomes more complicated when financing costs depend on the purchase price. In that case, calculate financing using a trial purchase price, update the MAO, and repeat until the result stabilizes. Alternatively, build a spreadsheet that calculates interest from the proposed loan amount automatically.

Do not count the same expense twice. If loan payments already include interest in the holding-cost line, remove that interest from the separate financing calculation. Likewise, keep contingency inside the renovation total when calculating profit and MAO.

Worked examples

Consider this simplified, illustrative analysis. The figures below are assumptions for demonstrating the method, not a market forecast or a recommended budget.

• Estimated ARV: $360,000
• Purchase price: $220,000
• Purchase closing and acquisition costs: $4,000
• Base renovation estimate: $48,000
• Renovation contingency: $7,200
• Financing costs: $18,000
• Holding costs: $12,000
• Selling costs: $21,600

Total project costs are $330,800. The projected profit is therefore $29,200, calculated as $360,000 minus $330,800. If the target profit is $35,000, the deal does not meet the target at the assumed purchase price.

Using the same assumptions, a simplified MAO is $214,200: $360,000 ARV minus $21,600 selling costs, $55,200 renovation cost including contingency, $18,000 financing, $12,000 holding costs, $4,000 acquisition costs, and the $35,000 target profit. If financing changes with the purchase price, refine this figure using the lender’s actual terms.

Now test a downside case. Reduce the expected sale price, increase the renovation budget, or extend the timeline. If a modest change eliminates the profit, the analysis is sensitive and the offer may need a larger margin of safety. This sensitivity check is often more informative than the original projected profit.

For specialized renovation decisions, compare the cost and buyer impact of alternatives rather than assuming the most expensive finish is best. The guides to kitchen remodel ROI and bathroom remodel ROI can help organize those trade-offs.

When to recalculate

Recalculate the deal whenever a major input changes, and always update the model before committing additional capital. Practical triggers include:

• A contractor provides a formal bid or changes the scope.
• Inspection reveals structural, water, electrical, plumbing, HVAC, or roof issues.
• Permit requirements add design, review, or construction costs.
• The lender changes the rate, points, draw schedule, or loan amount.
• The project runs beyond the original completion date.
• Comparable renovated listings suggest a different ARV or time on market.
• Material, labor, insurance, tax, utility, or selling expenses change.
• The expected listing price, buyer concessions, or marketing plan changes.

Maintain three versions of the analysis: base case, downside case, and—if useful—an upside case. The downside case should use assumptions you could realistically encounter, not an extreme scenario designed only to make the deal fail. Revisit the model at acquisition, after the scope is finalized, at major construction milestones, before listing, and whenever the project falls behind schedule.

Before making an offer, print or share the assumptions with your contractor, lender, and partners. Confirm which costs are included, who is responsible for each item, and what evidence supports the ARV. A calculator is most valuable when it exposes unanswered questions early. Use the fix-and-flip deal analyzer checklist to complete the review, then update the workbook as facts replace estimates.