Renovation Mortgage Calculator

A renovation mortgage rolls the purchase price and the rehab budget into a single loan, but the deal only survives if the finished value supports it. This calculator builds the full project budget with contingency and permits, prices the monthly payment, tests the investor 70% rule, rates the project’s viability, and compares six renovation loan programs side by side on your own numbers.

Quick Answer

How to use the renovation mortgage calculator

Fill in the deal as you understand it, then click Calculate. Nothing computes until you click, and the calculator above is pre-filled with the worked example so you can see a complete run first.

1. Price, rehab, and ARV: enter the purchase price, your renovation budget, and the after-repair value. ARV is the single most influential input: get it from a real appraisal or recent comps for renovated homes nearby, not from optimism.
2. Home size, only if you want it: square footage feeds the cost-per-sq-ft readout. It never touches the loan math, so leave it blank without affecting a single dollar elsewhere.
3. Down payment, rate, term: your cash in, the annual rate, and the amortization length. An empty term field assumes 30 years.
4. Pick your loan program: FHA 203(k), HomeStyle, conventional, VA, HELOC, or hard money. Your pick is highlighted in the comparison table so you can read its row against the other five.
5. Closing, timeline, contingency, holding, permits: the soft costs most buyers forget. Timeline multiplied by monthly holding costs is the true price of a slow renovation, and the contingency defaults to 10% if you leave it blank.
6. Read the verdict: the colored badge names the project’s viability from Excellent to Poor, and the detail lines show the budget, the payment, the loan-to-ARV, the 70% rule check, and the ROI that produced it.

The formulas: every number the tool produces

The calculator runs one pipeline from your inputs to the verdict, with nothing hidden in between.

The viability rating follows fixed thresholds on those results: Excellent needs a profit, ROI above 15%, and loan-to-ARV at or under 70%. Good covers profitable deals that miss one of those bars, either an ROI above 15% with leverage over 70%, or an ROI above 10%. Fair is a thin profit (ROI at or under 10%) or an exact break-even. Poor is any projected loss. The standard mortgage payment calculator prices a plain purchase loan the same way this tool prices the renovation loan itself, if you ever want to check the amortization figure against a second source.

Worked example: four runs, from excellent to poor

The pre-filled run is the worked example: buy at $200,000, renovate for $75,000, ARV $350,000, a 2,000 sq ft home, $15,000 down, 7% for 30 years, FHA 203(k), $8,000 closing, a 6-month timeline, 10% contingency, $1,200 a month in holding costs, and $1,500 in permits. The walk-through below follows the tool’s own pipeline: contingency is $75,000 × 10% = $7,500, the renovation budget is $75,000 + $7,500 + $1,500 = $84,000 ($42.00 per sq ft), the project costs $200,000 + $84,000 + $8,000 = $292,000, and the loan is $292,000 − $15,000 = $277,000 at $1,842.89 a month. The 70% rule fails ($284,000 against $245,000), loan-to-ARV is 79.1%, and the $73,000 of projected equity on $30,200 of cash is a 241.7% ROI with $50,800 of net profit. Because leverage runs past 70% of ARV, the verdict is Good rather than Excellent: the deal works, but you are paying close to full retail for the project.

Every row below is a verified run of the calculator above, chosen to show each viability tier:

The Poor run is the honest use of this tool: a $400,000 purchase with $100,000 of work against a $350,000 ARV borrows 143.7% of the finished value and projects a $175,200 loss. The Fair run shows the other edge the rating handles, an exact break-even at $0.00 of profit, which the tool files as Fair rather than Poor. And on the cost-per-square-foot readout, the renovation costs per square foot calculator digs into that single figure in more depth when you are benchmarking contractor bids.

FHA 203(k): Limited vs Standard

The 203(k) is the federal program for buying a fixer-upper with one FHA-insured loan, and it comes in two versions with different ceilings.

Limited 203(k) covers smaller, non-structural repairs and lets borrowers finance up to $75,000 of rehabilitation into the mortgage, with no consultant required and faster closings. Standard 203(k) handles major structural work: the rehabilitation must cost at least $5,000, there is no fixed dollar cap on the work itself beyond FHA loan limits, and a HUD-approved 203(k) consultant prepares the work write-up, inspects the draws, and shepherds the job. Both roll a 1.75% upfront mortgage insurance premium into the loan balance at closing, both charge annual MIP around 0.55%, both need at least 3.5% down for qualifying borrowers, and both are primary-residence only. The comparison table below applies exactly that MIP treatment to the FHA row, which is why it reads higher than the HomeStyle row at the same rate. HUD’s own 203(k) program page and its program-types breakdown are the authoritative source for the current caps.

HomeStyle, HELOC, and the alternatives

Fannie Mae HomeStyle is the conventional counterpart: a single loan covering purchase plus renovation with cancelable mortgage insurance, down payments as low as 3% for first-time buyers, and no 203(k) restriction to primary residences, so second homes and investment properties qualify. Renovation costs are capped relative to the as-completed value, and the work must be permanently affixed to the property. A HELOC is the right tool when you already own the home and have equity: usually a 10-year variable-rate draw as a second lien, cheaper and faster for small projects, but it is not a 30-year fixed mortgage and the tool prices it on your 30-year terms only as a baseline. If your HELOC thinking is further along, the HELOC strategy calculator models the draw-and-repay behavior this comparison table does not attempt.

Hard money closes in days and funds what banks will not, at much higher rates and 6 to 24 month terms: only use it with a certain exit, usually a refinance or a sale. VA renovation loans let eligible veterans roll purchase and repairs into one mortgage with no down payment and no monthly mortgage insurance, but they carry a VA funding fee, require the primary residence, and the work must be finished quickly. Standard construction mortgage calculator math applies when the project is new construction rather than a renovation, since renovation loans are underwritten against an existing structure’s after-repair value.

The 70% rule, honestly

Investors use the 70% rule, pay no more than 70% of ARV minus repair costs, as a margin-of-safety filter, not a law of nature. In the worked example the rule fails and the deal still projects $50,800 of profit, which tells you what the rule is really measuring: how much cushion you have when the ARV estimate is wrong, the timeline slips, or the budget overruns. The rule in this tool compares purchase price plus the full renovation budget (contingency and permits included, closing excluded) against 70% of ARV, and the verdict treats a failed 70% check as a downgrade rather than a veto. A deal that passes the rule with real comps behind the ARV is a deal that can survive one thing going wrong. A deal that fails it, like the worked example, needs everything to go right.

What competing calculators miss

Most renovation loan tools answer a narrower question than buyers actually ask:

• HomePaymentCalc’s renovation loan comparison: the strongest rival, comparing 203(k), HomeStyle, HELOC, personal loans, and cash-out refinance with credit-score eligibility and a best-fit picker. It is framed around refinancing an owned home with an existing mortgage balance, not a purchase deal judged against ARV: no 70% rule, no renovation budget building, no ROI or viability rating.
• The 203(k)-only estimators (loan-calculators.org, amortizationschedule.org, mortgage-calculator.net): solid single-loan tools with amortization schedules and MIP math, and the last of the three matches this page’s FHA treatment closely. All of them stop at one loan type: no ARV analysis, no alternative programs, no project economics.
• beyouthful’s FHA rehab calculator: the cleverest of the single-loan tools, auto-adjusting MIP by credit score and flagging Standard versus Limited automatically. It is still 203(k)-only, so an investor comparing programs has to run it repeatedly by hand.
• HUD-sourced guides (legalclarity’s mortgage explainers): accurate on program rules, the $75,000 Limited cap, and the 110% of after-improved-value loan basis, but they are explainers with no tool attached.
• The gap this page fills: the only page that builds the renovation budget with contingency and permits, judges the deal against ARV with the 70% rule, prices six programs on the reader’s exact loan amount, and turns all of it into a viability verdict and a cash ROI, every number reproducible in the tool above.

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