How Much Cash Flow Is Good for a Rental Property?

The per-door folklore

Ask a forum and you'll hear "$100–$200 per door per month." It's a fine gut-check, but it hides two things. First, what it costs you to get it: $200/month on a $30,000 down payment is a very different investment than $200/month on $120,000 down. Second, whether it's real: cash flow quoted before vacancy, maintenance, CapEx and management isn't cash flow — it's rent minus mortgage, and it evaporates the first time a water heater fails.

Benchmarks that hold up

After all operating expenses and the full mortgage payment:
• Negative— you own a bet on appreciation. Sometimes rational, never "cash flow."
• $0–$150/mo per unit — thin. Fine if the loan is amortizing fast or the market is appreciating; fragile otherwise.
• $150–$300/mo per unit— solid for most single-family and duplex deals at today's rates.
• $300+/mo per unit — strong; typically means an excellent buy, a big down payment, or higher-risk market pricing built in.

The two numbers that matter more

Dollars per door can't be compared across deals — returns can. Cash-on-cash return(annual cash flow ÷ total cash invested) tells you what your money earns: many investors target 6–10% in today's market, higher in cash-flow markets. And DSCR tells you how safe that cash flow is — see what counts as a good DSCR. A deal with $250/door but a 1.05 DSCR is more fragile than one with $180/door and a 1.40 DSCR.

Compute it honestly, in minutes

The math isn't hard — it's the discipline of including every line that's hard. The free rental calculator applies vacancy, management, maintenance and CapEx the way professional underwriters do (on gross scheduled rent, never double-counted), shows monthly cash flow after the full mortgage, and grades the whole deal A–F so a juicy-looking number can't hide a thin margin.