Buying a rental property in late 2026 is a spreadsheet decision, not a gut decision. Financing costs remain elevated, rent growth has cooled, and tenants have more options than they did a few years ago. Good deals still exist, but they only reveal themselves to investors who underwrite honestly. Here is the process worth holding every deal to, and the numbers that decide it.
Underwrite the Expenses First
Never trust a pro forma you did not build. Listing packets and seller spreadsheets exist to sell the property, and they understate expenses far more often than they overstate them. Before you look at a single return metric, rebuild the expense side line by line.
Start with property taxes as they will be assessed after your purchase, not the seller's current bill. Get an insurance quote in writing for the actual property, because a guess is not a number. Add management fees even if you plan to self-manage, since your time is not free and your eventual buyer will underwrite management. Then layer in routine maintenance, capital reserves for the roof, water heater, and HVAC, leasing fees, any utilities the owner pays, and association dues if they apply.
If a deal only works when you skip one of those lines, the deal does not work.
The 50 Percent Rule Is a Screen, Not an Underwrite
Use the 50 percent rule for what it is, a thirty-second filter. It assumes operating expenses, everything except the mortgage, will consume about half of gross rent over time. It earns its place because investors chronically forget vacancy, turnover, and capital items.
Respect its limits. A newer property in a low-tax area with tenants paying all utilities can run well below half. An older property with high taxes, rising insurance premiums, and owner-paid utilities can run above it. The rule cannot see any of that. Screen with it, then underwrite with your own line items. If your detailed budget lands far below half of rent, assume you missed something and go find it.
Cap Rate Describes the Property, Not Your Deal
Know what each return metric can and cannot tell you. Cap rate is net operating income divided by purchase price, with no financing in the formula. That makes it the right tool for comparing one property against another and judging whether a price is reasonable for the income, and the wrong tool for deciding whether the deal makes you money.
