What this BRRRR calculator measures
BRRRR is four steps in one check. You buy, you rehab, you rent, and you refinance. The useful result is not the rent alone. It is how much of your cash is still stuck in the property after the new loan, and whether the rent covers the new payment. This BRRRR calculator reports cash left, cash back, and year-1 cash-on-cash.
Cash left is never negative. When the refinance returns every dollar you put in, cash left is zero and any extra shows as cash back. Cash-on-cash is year-1 cash flow divided by the cash still left. If no cash remains, cash-on-cash is blank, because you cannot divide by zero. A blank ratio with cash back is a different outcome from a loss.
The free inputs are purchase, rehab, after-repair value, and monthly rent. Vacancy, operating expenses, the bridge, and the refinance stay on the defaults in the worked example. Change rent and you change income. Change ARV and you change the refinance proceeds. Change purchase or rehab and you change both the cash you put in and the bridge loan.
Formula
The bridge loan is a percent of purchase plus rehab. On the default it is 90%. Points are a percent of that loan. Interest over the hold is the loan times the annual rate times the fraction of the year you hold. Holding cost is the monthly holding figure times the months. Cash invested adds purchase, rehab, buying costs, points, interest, and holding, then subtracts the bridge loan.
The refinance loan is a percent of after-repair value. The default is 75%. Refinance closing costs are a percent of the new loan. Cash from the refinance is the new loan minus those closing costs and minus the bridge payoff. Cash left is the cash invested minus cash from the refinance, floored at zero. Cash back is the amount beyond the dollars invested, floored at zero.
Year-1 income starts from monthly rent times twelve, minus vacancy. Operating expenses add taxes, insurance, and the maintenance, management, and capital-reserve percents of effective rent. NOI is effective income minus those expenses. Debt service is the amortizing refinance payment times twelve. Cash flow is NOI minus debt service. Cash-on-cash is that cash flow divided by cash left.
Example
Worked example
Illustrative example. Cash left in, cash back, and cash-on-cash below come from sample loan and rent inputs, not from a refinance that funded.
The worked example is the BRRRR calculator default. Purchase $200,000, rehab $40,000, after-repair value $320,000, and rent $2,200 a month. The bridge is 90% of purchase plus rehab at 12% interest with 2 points, held 6 months, with $450 a month of holding costs and $4,000 of buying costs. The refinance is 75% of ARV at 7% for 30 years, with closing costs of 2% of the new loan. Vacancy is 5%. Maintenance and management are each 8% of effective rent. Taxes are $2,400 and insurance is $1,200. Cash left in the deal is $28,780. Cash back at the refinance is $0. Year-1 cash-on-cash is -5.88%. Year-1 cash flow on this sample is -$1,694 after debt service of $19,161.
If cash left is large, the refinance did not return the cash. A lower ARV, a lower refinance LTV, or a higher purchase will do that. If cash back is large, you still have to ask whether a lender will actually refinance at 75% of the ARV you typed, and whether the rent survives vacancy. The headlines do not call the lender.
Contractor assumptions
Rehab is a lump sum, the same way it is on the fix and flip calculator. The BRRRR page does not build a scope, and it does not import a cost database. The default rehab is $40,000. Replace it with the bid you have. This page is not a proposal for this property, and it does not set your budget.
The hold is six months on the sample, and holding costs are $450 a month on top of the bridge interest. Those months assume the work finishes and a tenant is in place in time for the refinance story you are telling. If the rehab runs long, interest and the monthly holding line keep accruing. Change the hold in the paid calculator. The free page keeps six months so the formula stays visible.
Rent is the rent you type. The engine does not know the lease, the street, or whether a short-term rental is legal there. Vacancy is 5% even if you believe the unit will never sit empty. Maintenance and management are each 8% of effective rent. Set them to your property manager's actual quote in the paid calculator if 8% is wrong.
Common pitfalls
Treating cash back at the refinance as money you can spend assumes a lender funds the loan-to-value and rate you typed. If the appraisal or the rate is worse, cash left in the deal rises.
Rent typed before vacancy, repairs, and management makes the year-1 cash-on-cash look stronger than the rental math. The sample already removes those lines. Zeroing them out is a different deal.
What stays on the subscription
The paid BRRRR calculator adds bridge rate, points, hold, vacancy, every operating line, refinance LTV, rate, term, and closing costs, plus saved deals. The free page keeps those on the defaults and shows only the three headlines. Standard is $9.99 a month after the 48-hour trial. Founding is $5.99 a month for the first 100 subscribers and stays at that price while the subscription is active.
These figures are estimates from the numbers on the page. They are not a commitment from a lender to refinance, and they are not a promise of rent. Check the loan terms and the lease before you treat cash back as money you can spend.
Questions
What does this BRRRR calculator show for free?
Cash left in the deal, cash back at the refinance, and year-1 cash-on-cash. Purchase, rehab, ARV, and rent are the inputs you can change. The bridge and the new loan stay on the published defaults.
Why can cash-on-cash be blank?
Cash-on-cash divides year-1 cash flow by the cash still in the deal. When the refinance returns all of that cash, the denominator is zero, so the ratio is left blank and cash back carries the result.
Is the refinance guaranteed?
No. The calculator applies the LTV, rate, and closing percent you are using. A lender can refuse the loan, cut the LTV, or delay it. Cash back is arithmetic, not an approval.
How is rehab treated?
As one lump sum added to the purchase before the bridge LTV is applied. There is no line-item cost book. Use the contractor's number, with contingency inside it if you want contingency.
Where do I change vacancy and the refinance rate?
In the paid calculator. The free page locks vacancy at 5% and the refinance at 75% of ARV, 7%, 30 years, and 2% closing, so the headlines stay tied to a written formula.