BRRRR Cash Flow Calculator: Model Your Numbers Before You Buy
Quick Answer
Model BRRRR cash flow in five numbers: Gross Monthly Rent − Vacancy Allowance (8%) − Management Fee (10%) − Maintenance Reserve (1% of value annually ÷ 12) − Mortgage Payment (at refinance terms) = Net Monthly Cash Flow. Positive cash flow after all deductions is required. Negative cash flow is a deal-killer regardless of equity position.
Cash flow is the BRRRR strategy's oxygen. A property that is cash-flow negative after refinance is a liability masquerading as an investment, consuming capital every month regardless of paper equity gains.
The gross-to-net calculation: Start with gross monthly rent. Deduct: vacancy allowance (budget 8% of gross rent for vacancy even in strong rental markets), management fee (8–12% of collected rent), maintenance reserve (1% of property value annually divided by 12 — for a £200,000 property this is £167/month), buildings insurance (£50–£150/month), ground rent and service charge if leasehold, and the refinance mortgage payment.
What positive cash flow looks like: on a £200,000 ARV property rented for £1,200/month with a £150,000 refinance mortgage at 5.5% interest-only, monthly cash flow typically works out as: £1,200 gross − £96 vacancy − £120 management − £167 maintenance − £80 insurance − £688 mortgage = £49 net. This is a thin but positive position — and the property is now asset-backed, cash-flowing, and your capital is recovered.
The cash flow stress test: run the numbers with rent 10% lower and mortgage rate 1% higher. If the deal goes negative under these conditions, your DSCR (Debt Service Coverage Ratio) is insufficient. Most institutional lenders require minimum 1.25× DSCR.
Analyse Any Property in Seconds
BuildIQ applies institutional-grade analysis to any address — instantly.
Start Free Analysis →