Why It Matters
You hear about a duplex listed at $185,000. Before pulling comps, calling your lender, or building a spreadsheet, you do one calculation:
Monthly Rent / Purchase Price x 100 >= 1%
If the duplex rents for $1,850/month or more, it passes. If it rents for $1,400/month, that's 0.76% — and you know the cash flow math is going to be tight before you spend another minute on it.
That's the entire point of the 1% rule. It's a 10-second filter, not a 10-page analysis. Properties that meet 1% tend to cash flow after expenses. Properties that don't can still be profitable — through appreciation, tax benefits, or forced equity — but they rarely throw off monthly cash from day one.
The rule doesn't account for taxes, insurance, vacancy, or maintenance. It doesn't know whether the neighborhood is appreciating or declining. It's a screening tool that tells you whether a deal deserves deeper analysis, not whether you should buy it.
At a Glance
- Formula: Monthly Rent / Purchase Price x 100 — target is 1% or higher
- Quick example: A $200,000 property should rent for at least $2,000/month
- What it screens for: Likelihood of positive monthly cash flow after typical expenses
- What it ignores: Property taxes, insurance, maintenance costs, vacancy rates, and appreciation potential
- Where it works best: Midwest and Southern markets where rent-to-price ratios naturally run higher
- Where it fails: Coastal and high-appreciation markets where properties trade at 0.4%-0.7% ratios but still build wealth through equity growth
Monthly Rent / Purchase Price x 100 >= 1%
How It Works
The math is intentionally simple. Take the monthly gross rent and divide by the total purchase price. A $175,000 single-family renting at $1,750/month hits exactly 1.0%. A $320,000 triplex renting at $2,880/month comes in at 0.9% — close, but below the threshold. The formula works whether you're screening a $95,000 duplex in Memphis or a $450,000 townhouse in Denver.
Why 1% predicts cash flow. The math behind the rule assumes roughly 50% of gross rent goes to operating expenses — taxes, insurance, repairs, vacancy, and property management. If rent is 1% of the purchase price, the remaining 50% (0.5% of purchase price per month, or 6% annually) usually covers a conventional mortgage payment with room left over. Drop below 1% and that cushion disappears. At 0.7%, most financed properties run negative after all expenses are accounted for.
The denominator matters. For a standard purchase, use the total acquisition price. For a BRRRR deal, the relevant number is your all-in cost — purchase price plus rehab costs — because that's the capital you have at risk. A $120,000 house needing $40,000 in renovations is a $160,000 deal, and rent needs to hit $1,600/month to clear the threshold.
Companion rules sharpen the picture. The 2% rule (monthly rent equals 2% of purchase price) was realistic in the aftermath of the 2008 crash but is nearly extinct in 2026 except in the roughest neighborhoods. The 50% rule says half your gross rent goes to expenses — pair it with the 1% rule and you get a fast cash flow estimate without a spreadsheet. A $200,000 property at 1% rents for $2,000/month; the 50% rule leaves $1,000 for debt service. If your mortgage payment is $950, you're looking at $50/month in cash flow — thin, but positive.
It's a filter, not a verdict. The 1% rule tells you whether to keep analyzing. A property at 1.2% in a B+ neighborhood with stable tenants deserves full underwriting. A property at 0.6% in a high-cap-rate market might still work if your strategy is appreciation plus tax benefits. The rule eliminates the bottom of the funnel — the deals that can't cash flow under any reasonable expense assumption — and saves your time for the ones that might.
Real-World Example
Ben Nakamura is screening three properties in different markets for his first rental purchase. He runs the 1% test on each:
Property A — Indianapolis duplex, $165,000: Both units combined rent for $1,750/month. $1,750 / $165,000 = 1.06% — passes the 1% rule.
Property B — Austin condo, $285,000: Market rent is $1,680/month. $1,680 / $285,000 = 0.59% — fails by a wide margin.
Property C — Cleveland single-family, $112,000: Rents for $1,175/month. $1,175 / $112,000 = 1.05% — passes.
Ben digs deeper into Properties A and C. For the Indianapolis duplex, he estimates expenses at 50% of rent ($875/month) and his mortgage payment at $790/month. That leaves $85/month in estimated cash flow — thin, but workable as a first deal.
The Austin condo? Even before running expenses, Ben knows the math. At 0.59%, roughly $840/month goes to expenses, leaving $840 for a mortgage payment that's actually $1,430/month on a $285,000 property. He'd be negative $590/month from day one. The deal only works if appreciation averages 5-6% annually — a bet on the market, not a cash-on-cash return play.
The 1% rule didn't tell Ben which property to buy. It told him which property not to spend a weekend analyzing.
Pros & Cons
- Screens deals in seconds — One division tells you whether a property deserves deeper analysis, saving hours of spreadsheet work on deals that will never cash flow
- Works across property types — Applies to single-family, duplex, triplex, and small multifamily equally since it's a ratio, not an absolute number
- Easy to remember and communicate — "Does the rent hit 1% of the price?" is a question any investor can ask their agent, and any agent can answer immediately
- Filters out appreciation-only bets — Properties far below 1% are almost always negative cash flow with conventional financing, forcing you to acknowledge the strategy is equity growth, not income
- Scales to market-level screening — You can apply the 1% test to an entire metro's median rent-to-price ratio before choosing which markets to analyze individually
- Ignores expense variation by market — A 1% property in Texas (high property taxes, 2.5%+ of value) cash flows very differently from a 1% property in Nevada (no state income tax, lower insurance)
- Penalizes high-appreciation markets — San Francisco, Seattle, and Austin routinely fail the 1% test but have delivered 6-8% annual appreciation for decades, building wealth through equity rather than monthly income
- Doesn't account for financing terms — A 1% property with a 7.5% mortgage rate cash flows differently than the same property at 5.5%, but the rule treats both identically
- Misleading in distressed neighborhoods — Properties in D-class areas often exceed 1.5-2% because purchase prices are low, but high vacancy, turnover, and maintenance costs eat the apparent margin
- Static snapshot of a dynamic market — Rents increase, prices fluctuate, and interest rates shift quarterly. A property at 0.9% today might hit 1.1% after a lease renewal
Watch Out
Don't use the 1% rule as your only analysis. It tells you whether to keep looking at a deal — it says nothing about the deal's actual return. A property hitting 1.2% in a high-crime area with 15% vacancy and $3,000/year in deferred maintenance repairs will bleed cash despite passing the screen. Always follow a passing 1% test with a full cash flow analysis including rental income, real expenses, and debt service.
Adjust the denominator for rehab deals. Applying the 1% rule to the purchase price alone on a value-add deal is misleading. A $90,000 house renting at $1,100/month looks like a 1.22% winner — until you add the $45,000 renovation budget. At $135,000 all-in, the ratio drops to 0.81%. Use total capital invested as your denominator, or the 1% rule will send you into deals that hemorrhage cash during the stabilization period.
Know your market's baseline. If every property in your target market sits at 0.6-0.7%, the 1% rule isn't broken — your market is. Coastal California, the Pacific Northwest, and parts of the Northeast are appreciation markets where cash flow screening rules from the Midwest don't apply. Shift your analysis to total return (appreciation + equity paydown + tax benefits) rather than forcing a cash-flow filter onto an appreciation strategy.
Ask an Investor
The Takeaway
The 1% rule is the fastest screening tool in rental property investing — one calculation that filters out deals unlikely to cash flow before you spend hours on full underwriting. Monthly rent divided by purchase price, target 1% or higher. It works best in Midwest and Southern markets where rent-to-price ratios naturally support cash flow. It breaks down in coastal markets, distressed neighborhoods, and rehab deals where the real denominator is higher than the sticker price. Use it as the first gate in your deal funnel, never the last. A property that passes the 1% test earns a deeper look. A property that fails it needs a different thesis — appreciation, forced equity, or tax strategy — to justify the negative monthly cash flow you're signing up for.