Enter the Deal
Purchase price, down payment, expected rent — the numbers the listing shows you.
100% Client-Side · Your Financial Data Never Leaves
A duplex ROI calculator strips away optimistic gross rental yield to reveal your true monthly cash flow after vacancy, maintenance, CapEx reserves, property management fees, insurance, and mortgage. It compares house-hacking scenarios where you live in one unit and rent the other.
Property Details
ROI Breakdown
Where Your Rent Check Goes
Enter your numbers to see the cost waterfall.
Results update in real-time as you type.
Key Metrics
Monthly Mortgage (P&I)
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True Monthly Cost
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Your Out-of-Pocket / mo
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Cash-on-Cash Return
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Cap Rate — Rented Unit Only
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Gross Yield — Rented Unit Only
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Net Operating Income
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Total Cash Invested
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Equity vs. Sunk Costs — 10 Year Outlook
The 10-Year Projection
| Year | Property Value | Loan Balance | Equity | Annual Costs | Rent Collected | Net Annual | Cumulative Cash-on-Cash |
|---|---|---|---|---|---|---|---|
| Enter your property details above to generate the 10-year projection. | |||||||
Should You House-Hack or Just Rent?
How It Works
Add the Hidden Costs
Vacancy, maintenance, CapEx, and management — the costs real estate gurus conveniently skip.
See the Real Numbers
Watch your "cash-flowing" duplex actually cost you $400–$800/month out of pocket.
Track the Long Game
Equity growth, appreciation, and cumulative cash-on-cash year by year. The rent-vs-own card answers the separate question of when owning beats renting.
Real Estate Investor Essentials
When analyzing a duplex or multi-family property, never trust the seller's pro-forma numbers. To accurately measure your rooms and verify the square footage during a walkthrough, carry a professional laser distance measure. Once you close on the property, installing a smart leak detection system under every sink and water heater is the highest ROI upgrade you can make to prevent catastrophic water damage while you are away from the rental unit.
What is the True ROI of House Hacking?
House hacking—buying a multi-family property like a duplex, living in one unit, and renting out the other—is often pitched as a way to "live for free." While it can dramatically reduce your housing expenses, many new investors fail to account for the true costs of homeownership. Gross Rental Yield only looks at the rent collected versus the purchase price. A true ROI calculation must include Capital Expenditures (CapEx) for big-ticket items like roofs and HVAC systems, monthly maintenance reserves, property management fees (even if you self-manage, your time has value), and vacancy rates. HouseHack strips away the optimistic pro-forma projections to show your actual out-of-pocket costs and cash-on-cash return, giving you a realistic 10-year equity projection.
Frequently Asked Questions
What is house hacking with a duplex?
House hacking means buying a multi-unit property (typically a duplex), living in one unit, and renting out the other. The rental income offsets your mortgage payment, potentially letting you live for free or near-free while building equity. FHA loans allow duplex purchases with as little as 3.5% down, but every loan below 20% down carries mortgage insurance, so add it to the payment before you compare that payment to your current rent.
What is a good cap rate for a duplex investment?
Cap rates for duplexes typically range from 4-8% depending on location. In high-demand metro areas, 4-5% is common. In smaller cities and suburbs, 6-8% is achievable. Read that band carefully against this page: published cap rates are compiled from fully-rented comparables, while the Cap Rate card here counts the rented unit only over the whole purchase price, because the form asks for a single rent. Cap rate also ignores financing entirely, so cash-on-cash return after mortgage payments is the more useful figure for a leveraged buyer.
Do I need mortgage insurance on a duplex with less than 20% down?
Yes, on any loan below 20% down. FHA charges an up-front premium of 1.75% of the base loan, normally financed into the mortgage, plus an annual premium of 0.55% for a 30-year loan above 95% LTV under HUD Mortgagee Letter 2023-05. That annual premium runs the full term above 90% LTV and 11 years below it, so it does not fall off inside a 10-year projection either way. Conventional loans carry no up-front premium, and the annual premium is cancellable once the balance reaches 80% of the original value. This calculator adds both to your true monthly cost; leave the rate blank to use the published default for the loan type.
What hidden costs do duplex investors underestimate?
The five most commonly underestimated costs are: vacancy (budget 5-8% of annual rent), maintenance and repairs (budget 5-10%), capital expenditure reserves for roof/HVAC/plumbing (budget 5%), property management if you ever stop self-managing (8-10%), and landlord insurance premiums (typically 25% more than homeowner's insurance).