?? 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

Purchase
Income
Monthly Costs
Hidden Reality Checks
Growth Projection

?? 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) —
True Monthly Cost —
Your Out-of-Pocket / mo —
Cash-on-Cash Return —
Cap Rate —
Gross Rental Yield —
Net Operating Income —
Total Cash Invested —

Equity vs. Sunk Costs — 10 Year Outlook

?? The 10-Year Projection

Year Property Value Loan Balance Equity Annual Costs Rent Collected Net Annual Cumulative ROI
Enter your property details above to generate the 10-year projection.

?? Should You House-Hack or Just Rent?

How It Works

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Enter the Deal

Purchase price, down payment, expected rent — the numbers the listing shows you.

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Add the Hidden Costs

Vacancy, maintenance, CapEx, and management — the costs real estate gurus conveniently skip.

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See the Real Numbers

Watch your "cash-flowing" duplex actually cost you $400–$800/month out of pocket.

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Track the Long Game

Equity growth, appreciation, and the exact year it finally pays off — the full 10-year truth.

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.

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. However, cap rate alone does not account for financing costs — cash-on-cash return after mortgage payments is a more useful metric for leveraged investors.

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).