How to read a BRRRR project
BRRRR is buy, rehab, rent, refinance, repeat. Two projects hinge on one loan: first you fund the house and the work, then you find out whether the rent and appraisal support a new mortgage. That refinance is an application you have to win, not money in your account.
Add up the cash before the refinance
The model stacks purchase price, rehab, buying closing costs, and holding costs during the work. Then it builds a new loan from after-repair value times your refinance LTV, less refinance costs. It assumes you covered all that in cash, so handle any acquisition debt and its payoff separately. Get real bids and pad the timeline before you lean on an ARV.
Read cash left and monthly cash flow as two answers
Cash left in the deal is what's still tied up after the modeled refinance, floored at zero. When it hits zero there's no denominator for cash-on-cash, so the page shows N/A. That's a good day, not a free house; the new mortgage still comes due every month. Monthly cash flow rides on the rent you collect, the payment, and the expenses you entered.
Cash-on-cash puts a year of post-refinance cash flow against the cash you left behind. It says nothing about how long the project took, your income taxes, or what a sale would bring, and money you pull out at the refinance is borrowed, not earned.
Stress the refinance before you repeat
Knock the appraisal down. Trim the LTV. Nudge the rate up. See whether that leaves more cash stuck in the house or a monthly gap you'd have to cover. Ask lenders early how much rent they'll count, how long they want the loan seasoned, and what condition and guarantees they expect. The rental calculator handles the operating years, and the reserve calculator sizes the replacements ahead.
Line up your refinance lender while the drywall is going in, and the last R takes care of itself.