Real Excel formulas you can read and edit — not a locked demo, not a PDF, and not another web form that forgets your numbers when you close the tab.
Download the .xlsx (free) ↓Opens in Excel, Numbers, LibreOffice, or upload it to Google Sheets (File → Import). No macros.
Three tabs. Yellow cells are yours to type in, green cells calculate.
15 inputs → gross and effective income, operating expenses, NOI, loan amount, P&I payment, annual debt service, monthly cash flow, cap rate, cash-on-cash, DSCR, break-even rent and your rent cushion. Ends in a plain-English verdict that tells you to walk when the deal says walk.
A 4×4 grid of monthly cash flow at 100/95/90/85% of asking rent crossed with 5/8/12/15% vacancy. The best case is the one number every guru shows you; this tab is the other fifteen.
How to use it, and what DSCR, cash-on-cash, cap rate and break-even rent each actually tell you — in a paragraph each, no jargon.
6.9% rate, 6% vacancy, 10% maintenance, 8% management, 5% CapEx reserve. Most free templates quietly leave maintenance, CapEx and management out entirely — which is exactly why every deal looks good in them.
Because a calculator that vanishes when you close the tab is not how anyone actually buys a house. You need a file you can save next to the listing, email to your partner, and argue with. This one is genuinely free and genuinely unlocked — no watermark, no locked cells, no trial. If it saves you from one bad duplex it has paid for itself many times over.
If you end up wanting the multi-property comparison, the 10-year projection, the BRRRR/refi tab, the rehab budget and the exit math, that's the paid toolkit below. If you don't, keep the free one with our blessing.
Everything in the free file, plus multi-property comparison, a 10-year projection with amortisation and equity build, BRRRR/refinance math, a rehab budget with enforced contingency, the 48-point checklist as a tickable tab, and the written underwriting guide.
Run the numbers in your browser →
The 48-point due-diligence checklist →