BRRRR Calculator: How to Model a Deal Before You Commit
A BRRRR calculator models purchase, rehab, rent, and refinance in one place so you know how much capital comes back out before you make an offer. This guide covers every input, the three outputs that decide the deal, a fully worked example, and the sensitivity cases where a BRRRR leaves cash stranded.
BRRRR Calculator: How to Model a Deal Before You Commit
The number one reason BRRRR deals underperform is not a bad contractor or a slow appraisal. It is that nobody ran the numbers before the offer went in. The ARV was a guess, the rehab budget had no contingency, and the problem surfaced at the refinance, when the lender's loan amount came back $40,000 short of the capital already sunk into the property.
A BRRRR calculator removes that surprise by forcing every stage of the deal into one model before you commit: purchase, rehab, rent, refinance, and what is left over. This guide covers what to enter, the three outputs that actually decide whether a deal is worth doing, a fully worked example with realistic numbers, and the sensitivity cases where a BRRRR quietly fails to return your capital. If you need the strategy itself rather than the math, start with the full BRRRR strategy and how each stage works.
What a BRRRR Calculator Actually Does
A BRRRR calculator models all five stages of the strategy in sequence: purchase price and closing costs, rehab budget and holding costs, market rent and operating expenses, refinance LTV and the new mortgage payment, and finally cash left in the deal plus cash-on-cash return. The goal is to recover 80% to 100% of invested capital at refinance.
The difference between a BRRRR calculator and a standard rental analysis is the refinance. A buy-and-hold model asks whether the rent covers the mortgage. A BRRRR model asks that, and then asks a second question that determines whether you can do the next deal: how much of your capital comes back out.
Those two questions can pull in opposite directions, which is why running them separately produces bad decisions. A higher appraised value pulls more cash out and also raises the loan payment, which compresses cash flow. The calculator exists to show you both effects at once.
The Five Stages and What to Calculate at Each
Step 1: Buy. Total the purchase price, purchase closing costs, and any down payment or origination points if you are using acquisition financing. This is the first block of capital at risk.
Step 2: Rehab. Total the renovation budget plus a 20% contingency, then add holding costs for the full renovation window: hard money interest, taxes, insurance, and utilities while the property is vacant.
Step 3: Rent. Estimate market rent after renovation and subtract full operating expenses. The rent number has to survive contact with the post-refinance mortgage payment, not the pre-refinance one.
Step 4: Refinance. Estimate the after repair value from sold comps, apply the lender's LTV, and subtract the payoff of any acquisition loan and the refinance closing costs. What remains is your cash out.
Step 5: Repeat. Subtract cash out from total project cost. The remainder is your cash left in the deal, and it is the number that decides how quickly you can buy the next property.
Stages 1 through 3 are estimates you control. Stage 4 is decided by an appraiser and an underwriter you have never met. That asymmetry is the entire reason for building the model conservatively.
The Inputs: What You Need Before You Enter Anything
Purchase price: the contracted price or your target offer, not the list price. Model the offer you intend to make.
After repair value: the value once renovations are complete, supported by three to five sold comps from the last 90 days with matching square footage, bedroom count, style, and finish level. Active listings are asking prices, not evidence.
Rehab budget: an itemized contractor bid where possible. Absent a bid, estimate at $15 to $25 per square foot for cosmetic work and $40 to $60 per square foot for heavy work involving systems, layout changes, or structural repair. Add 20% on top of whichever figure you use.
Acquisition financing: hard money in 2026 typically runs 10% to 12.5% with 1.5 to 3 points on a 6 to 12 month term. Points are paid upfront and interest accrues for the full holding period, so a 3 month schedule slip is a real line item, not a rounding error.
Market rent: rental comps for the finished condition, cross-checked against what a local property manager says the unit will actually lease for. Model lease-up time as well: 30 vacant days is common and costs a full month of rent.
Operating expenses: property taxes from county records at the post-renovation assessed value, insurance quoted for the actual property, vacancy at 5% to 10%, maintenance reserve at 5% to 10%, and management at 8% to 10% of collected rent.
Refinance terms: LTV of 70% to 75% is standard on investment property cash-out, with 80% available to strong borrowers at some lenders. Rates on DSCR loans in 2026 have generally run 6.75% to 8.0% on a 30-year fixed. Most lenders also require a seasoning period of around six months before they will lend against the new appraised value rather than your purchase price.
The calculator is only as good as these numbers. Be conservative on ARV, conservative on rent, and generous on rehab.
The Three Outputs That Decide the Deal
Total project cost = purchase price + closing costs + rehab + holding costs. This is the capital that has to come back.
Cash out at refinance = (ARV × LTV) - acquisition loan payoff - refinance closing costs. Refinance closing costs run 2% to 3% of the loan amount and are the single most commonly omitted line in homemade spreadsheets.
Cash left in deal = total project cost - cash out at refinance. Under $20,000 on a small single-family deal is strong. More than 50% of your capital stranded means the deal is a rental purchase with extra steps, not a BRRRR.
Two supporting outputs finish the picture. Post-refinance monthly cash flow is rent minus operating expenses minus the new mortgage payment, and cash-on-cash return is annual cash flow divided by cash left in the deal. When cash left in the deal approaches zero, cash-on-cash return stops being meaningful and infinite returns get quoted. Judge those deals on monthly cash flow instead.
A Fully Worked Example
A distressed three bedroom single-family in a Midwest market, light to medium rehab covering kitchen, bathrooms, and flooring.
| Input | Value |
|---|---|
| Purchase price | $115,000 |
| Purchase closing costs | $3,500 |
| Rehab budget | $28,000 |
| Hard money, 11% for 8 months + 2 points | $10,200 |
| Total project cost | $156,700 |
| ARV from four sold comps | $185,000 |
| Market rent | $1,475/mo |
| Operating expenses | $565/mo |
| Refinance LTV | 75% |
| Refinance rate and term | 7.5%, 30-year fixed |
Operating expenses break down as taxes $175, insurance $100, management $140, maintenance $75, and vacancy $75.
Now the outputs. The refinance loan is $185,000 × 75% = $138,750, which at 7.5% over 30 years produces a payment of $970 per month. Cash left in the deal is $156,700 - $138,750 = $17,950, so roughly 89% of the capital comes back.
Monthly cash flow is $1,475 - $565 - $970 = negative $60. The deal recovers capital well and loses money every month. Cash-on-cash return is negative, so there is nothing to annualize.
Raise the rent assumption to $1,575 and the picture changes to $40 per month positive, a cash-on-cash return of $480 ÷ $17,950 = 2.7%. A $100 swing in monthly rent, well within the margin of error on most rent estimates, is the difference between a losing deal and a barely acceptable one. To reach an 8% cash-on-cash return on $17,950 of stranded capital, this property needs about $1,655 in rent, a 12% premium over the original estimate.
The debt coverage math tells the same story. At $1,475 rent against $1,245 of principal, interest, taxes, and insurance, the DSCR is 1.18. That clears most lender minimums of 1.15 to 1.25, but only just, which means this deal is exposed to any rate movement between offer and closing. Check the full DSCR qualification thresholds before assuming the refinance is approvable.
Sensitivity: The Cases Where a BRRRR Fails
One scenario is not analysis. Run three, and let the conservative case make the decision.
| Scenario | ARV | Total project cost | Loan at 75% | Cash left in deal | Monthly cash flow |
|---|---|---|---|---|---|
| Conservative (ARV 5% low, rehab 20% over, 9 month hold) | $175,750 | $163,500 | $131,813 | $31,700 | -$12 |
| Base | $185,000 | $156,700 | $138,750 | $17,950 | -$60 |
| Optimistic (ARV 5% high, rehab on budget) | $195,000 | $156,700 | $146,250 | $10,450 | -$113 |
Read the cash flow column left to right. It gets worse as the deal gets better. Every dollar of extra appraised value pulls more capital out and adds to the mortgage payment, and when rent is fixed, the payment increase lands directly on cash flow. The same trap catches the 80% LTV solution: at 80% of $185,000 the loan is $148,000, cash left drops to $8,700, and cash flow falls to negative $125 per month.
Negotiating the purchase price behaves differently. Buying at $105,000 instead of $115,000 drops total project cost to $146,700 and cash left in the deal to $7,950, while monthly cash flow stays at negative $60. Price concessions and higher LTVs fix capital recovery. Only rent, operating expenses, or a lower rate fix cash flow.
That is the diagnostic value of running the model properly. This particular deal is rent-constrained, not ARV-constrained, so chasing a better appraisal or a higher-LTV lender solves the wrong problem. The right moves are to verify whether $1,575 to $1,655 is achievable in that submarket, or to walk.
How to Run the Numbers on Your Own Deal
Three scenarios across five stages is roughly 40 linked calculations, and every one of them changes when a single input moves. Built in a spreadsheet, that is an hour per property and a formula error waiting to happen, which is why most investors run one optimistic case and call it analysis. The cost of that shortcut is not a bad spreadsheet. It is a $17,950 capital shortfall discovered six months after closing, when the options have run out.
ProPilot's Deal Calculator handles the full BRRRR cycle in one model. Enter purchase price, rehab budget, financing terms, ARV, rent, and expenses, and it returns cash left in the deal, post-refinance cash flow, DSCR, and cash-on-cash return together. Change the ARV or the rent and every downstream number updates, so building the conservative case takes seconds rather than a rebuilt spreadsheet. Auto Comps and Rent Estimates populate the two inputs most likely to be wrong, which is where guessing does the most damage.
Model your next BRRRR before the offer goes in, not after the appraisal comes back. Try it free for 7 days.
FAQ
What is a good BRRRR calculator output?
A strong BRRRR deal recovers 80% to 100% of invested capital at refinance, leaving $0 to $20,000 in the deal while producing positive cash flow after the new mortgage payment. If more than 50% of your capital stays stranded, or post-refinance cash flow is negative, renegotiate the purchase price or pass.
How do you calculate cash left in a BRRRR deal?
Cash left in deal = total project cost minus cash pulled out at refinance. Total project cost is purchase price plus closing costs plus rehab plus holding costs. Cash out is ARV multiplied by the lender's LTV, minus any acquisition loan payoff and refinance closing costs. Invest $156,700 and pull out $138,750, and $17,950 stays in.
What LTV can you get on a BRRRR refinance?
Most DSCR and conventional lenders offer 70% to 75% LTV on investment property cash-out refinances, with 80% available to borrowers with strong credit and reserves. The LTV applies to the appraised after repair value, not to your purchase price or total capital invested. Raising LTV also raises the payment, so check cash flow before chasing it.
How accurate does the ARV estimate need to be?
Accurate enough that a 5% miss does not break the deal. In the worked example above, a 5% low appraisal moved cash left in the deal from $17,950 to $31,700, a 77% increase in stranded capital. Use three to five sold comps from the last 90 days and model the low case before you write the offer.
Should the calculator include the rehab contingency?
Yes. Add 20% to any contractor estimate and put it in the base case, not a footnote. Renovation overruns are the most common cause of BRRRR capital shortfalls, and a contingency that only exists in the optimistic scenario is not a contingency.
Can a BRRRR deal work with negative cash flow?
Rarely, and only when capital recovery is near total and you have income covering the shortfall. A deal that returns 100% of your capital and loses $60 per month is a bet on rent growth. A deal that strands $30,000 and loses $60 per month is a mistake with a story attached.
The Bottom Line
Run three scenarios, not one. The base case tells you what you hope will happen, and the conservative case tells you what the deal survives. In the example above, the spread between them was $17,950 and $31,700 of stranded capital, which is the difference between buying again in three months and waiting a year.
Watch the two outputs that move in opposite directions. Cash left in the deal improves with a higher ARV, a higher LTV, and a lower purchase price. Post-refinance cash flow only improves with higher rent, lower expenses, or a lower rate. A deal that fails on cash flow will not be rescued by a better appraisal.
Model the deal before the offer, and the refinance becomes a confirmation rather than a verdict. Once the numbers work, the BRRRR strategy guide covers how to turn a single working model into a repeatable pipeline.
Run your next BRRRR deal through a full model before you commit capital. Try ProPilot free for 7 days.