The BRRRR strategy works on paper. Buy below market, rehab, rent, refinance, repeat. The problem is that "works on paper" and "works in your bank account" are two different things. The gap between them is a spreadsheet that models the full cycle with your actual numbers, not averages from a YouTube video.
I've run BRRRR numbers on properties where the back-of-napkin math said "great deal" and the spreadsheet said "you'll have $38,000 trapped in this property earning 3% cash-on-cash." The spreadsheet was right. Here's what a BRRRR calculator needs to show you and how to use it.
Every calculation in a BRRRR model flows from seven numbers. Get these wrong and every output is fiction.
The ARV is the highest-risk input. Overestimate ARV by 10% and your cash-out refi returns $15,000-$20,000 less than projected. Always use conservative comps. If you have to stretch to justify the ARV, the deal is telling you something.
Total cash needed to close and start the rehab. This is the capital you're trying to recycle.
Holding costs include hard money interest, insurance, taxes, and utilities during the rehab period. Budget 6 months of holding even if the contractor says 3.
Example: Purchase a distressed duplex for $120,000. Closing costs $3,600. Rehab budget $45,000 (including 15% contingency). Hard money at 12% interest-only on $120,000 = $1,200/month. Insurance and taxes during rehab: $450/month. Six months of holding costs: $9,900.
Total capital deployed: $120,000 + $3,600 + $45,000 + $9,900 = $178,500.
After rehab and lease-up, you refinance based on the improved value. This is where you find out if the BRRRR actually worked.
Most investment property cash-out refis are 70-75% LTV. DSCR lenders may go to 80% if the property's income supports it.
Continuing the example: ARV appraises at $230,000. At 75% LTV, the new loan is $172,500. Refi closing costs at 3%: $5,175. Hard money payoff (principal only, interest was paid monthly): $120,000.
Net cash returned: $172,500 - $5,175 - $120,000 = $47,325.
But you deployed $178,500 total. Cash left in deal: $178,500 - $47,325 - wait. The hard money payoff came from the refi proceeds, but the rehab and holding costs came from your pocket. Let me recalculate properly.
Cash out of your pocket: down payment on hard money (say 10% = $12,000) + rehab ($45,000) + holding costs ($9,900) + purchase closing ($3,600) = $70,500 from your cash.
Cash returned from refi (after paying off hard money and refi closing): $172,500 - $120,000 - $5,175 = $47,325.
Cash left in deal: $70,500 - $47,325 = $23,175.
That's a 67% capital return rate. Not bad, but not a full BRRRR. To get closer to zero cash left in, you'd need a lower purchase price, lower rehab cost, or a higher ARV. The spreadsheet shows you exactly which lever to pull.
Now you own a $230,000 duplex with a $172,500 mortgage. Does it cash flow?
Each unit rents for $1,100/month. Gross rent: $2,200/month. At a 7.2% rate on a 30-year fixed, the mortgage payment (P&I) is approximately $1,172/month. Property taxes: $320/month. Insurance: $140/month. Vacancy reserve (8%): $176/month. Maintenance reserve (5%): $110/month. Management (0% if self-managed, 10% if not): $0-$220/month.
Self-managed cash flow: $2,200 - $1,172 - $320 - $140 - $176 - $110 = $282/month.
Cash-on-cash return on the $23,175 left in: ($282 x 12) / $23,175 = 14.6%. That's strong. Try getting 14.6% in a savings account.
A single-scenario BRRRR calculation is a guess. A sensitivity analysis is a decision tool. The spreadsheet should show a grid: rows are different purchase prices, columns are different ARV outcomes. Each cell shows the resulting cash left in deal.
This grid answers the real question: how wrong can my ARV be before this deal stops working?
If the deal only works when ARV hits $230,000 exactly, you're gambling. If it still works at $210,000, you have margin. The sensitivity tab is where you earn or lose $20,000 before you make the offer.
All three are knowable before you make an offer. A good BRRRR calculator models each scenario so you see the damage before it happens.
Shopfolio's BRRRR Strategy Calculator models MAO, rehab budget, holding costs, refi scenarios, cash left in deal, and post-refi cash flow with sensitivity analysis. $29, one-time purchase.
See the BRRRR CalculatorWhat numbers do I need to run a BRRRR calculator?
You need seven inputs: purchase price, estimated rehab cost, After-Repair Value (ARV), expected monthly rent, estimated operating expenses (taxes, insurance, maintenance, management), hard money loan terms (rate, points, term), and refinance terms (LTV, interest rate, closing costs). With these seven numbers, the calculator can model every phase of the BRRRR cycle and tell you whether the deal returns your capital.
What is a good cash-left-in-deal number for a BRRRR?
Zero is the ideal. In practice, most successful BRRRR investors target under $10,000 or less than 10% of total project cost left in after the refi. If you're leaving 30-50% of your capital in the deal, the BRRRR didn't work as intended and you'd have been better off buying conventionally from the start.
Does BRRRR still work with high interest rates?
Yes, but the margin for error shrinks. At 7%+ mortgage rates, the monthly debt service on the refinanced loan is significantly higher than at 4%, which compresses your post-refi cash flow. The deals that still work at high rates have deeper discounts on purchase price (65-70% of ARV instead of 75%), lower rehab costs relative to value-add, or stronger rental markets where rents cover the higher payment. A BRRRR calculator shows you exactly where the break-even point falls at current rates.