Short answer: A BRRRR deal works when the cash-out refinance pays back most of what you spent. Add the purchase price, closing costs, rehab and holding costs, add the refinance closing costs, then subtract the new loan (after-repair value × loan-to-value). What is left is your cash still in the deal.
It uses the same formulas as FirstDoor's full deal score.
How the BRRRR math works
BRRRR means buy, rehab, rent, refinance, repeat. The whole strategy rests on one number: how much of your cash is still in the deal after the refinance.
Cash left in = purchase price + closing + rehab + holding costs + refinance closing costs − refinance loanThe refinance loan is the after-repair value (ARV) times the loan-to-value the lender allows. On loans sold to Fannie Mae, cash-out refinances of investment properties are capped at 75% LTV for one unit and 70% for 2–4 units. After the refinance, the property has to carry the new, larger loan, so the calculator scores cash flow, cash-on-cash and DSCR on the refinanced loan.
Worked example
The defaults are the illustrative deal from our BRRRR guide: buy for $150,000 with $4,500 of closing costs, rehab for $35,000, rent for $2,100/mo, then refinance at 75% of a $240,000 ARV on a 30-year loan at 7.40% (Freddie Mac PMMS, week of 2026-10-15; cash-out investment loans usually cost more).
| All-in cost | $189,500 |
| Refinance loan (75% of ARV) | $180,000 |
| Refinance closing costs (3% of loan, assumed) | $5,400 |
| Cash left in the deal | $14,900 |
| New principal & interest | $1,246 |
| Cash flow after refinance | $136/mo |
| Cash-on-cash on cash left in | 10.9% |
| DSCR | 1.11 |
At a 70% LTV, the limit for 2–4 units, the loan drops to $168,000 and $26,540 stays in the deal. Holding costs default to $0 because they depend entirely on your loan and timeline: add the interest, taxes, insurance and utilities you pay while the property sits empty. You can score the refinanced property in the full deal calculator.
Frequently asked questions
How do you calculate a BRRRR deal?
Add up everything you spend: purchase price, closing costs, rehab and holding costs. The refinance loan is the after-repair value times the lender's loan-to-value limit. Subtract the loan (net of its closing costs) from your total to get the cash left in the deal, then check that the rent still covers the new, larger payment.
What loan-to-value can you get on a BRRRR refinance?
On loans sold to Fannie Mae, cash-out refinances of investment properties are capped at 75% loan-to-value for one unit and 70% for 2–4 units. DSCR and portfolio lenders set their own limits.
How soon can you refinance after buying?
For loans sold to Fannie Mae, at least one borrower must be on title for six months, and a first mortgage being paid off must be at least 12 months old. The delayed financing exception allows earlier refinancing if you bought without a mortgage, with the new loan capped at your documented purchase investment.
What does infinite return mean in BRRRR?
If the refinance gives back all of your cash and the property still cash-flows, you have no money left in the deal, so cash-on-cash return has no denominator. That is the BRRRR goal, but it depends on the appraisal coming in at your ARV.
What does this calculator leave out?
Interest and fees on any short-term purchase or rehab loan unless you add them as holding costs, rent and expense growth, and taxes. The appraisal, not your estimate, sets the ARV, so try a lower ARV to see how much cash would stay stuck.