What is House Hacking?

House hacking is a real estate strategy where you buy a multi-unit property — typically a duplex, triplex, or fourplex — live in one unit, and rent out the others to reduce or eliminate your monthly mortgage payment. Because you occupy one unit, the property qualifies for owner-occupied financing: FHA allows as little as 3.5% down on 2-4 unit properties, and conventional loans go as low as 5% down — far below the 20-25% required for a pure investment property.

The key distinction between a rough estimate and a real house hacking analysis is accounting for vacancy and maintenance reserves. Units don't stay full year-round, and things break. This calculator forces you to model those realities so your projected net housing cost reflects what you will actually experience — not a best-case scenario.

How to Use the House Hacking Calculator

1. Enter your mortgage details. Input the purchase price, down payment, interest rate, and loan term to calculate your monthly PITI (principal, interest, taxes, insurance) payment.
2. Enter rental income from other units. Input the expected monthly rent for each unit you plan to rent out. Do not count the unit you will occupy.
3. Set vacancy and maintenance reserves. Standard vacancy reserve is 5–10% of gross rent; maintenance and CapEx reserve is 10–15%. These convert gross rental income into a realistic net figure.
4. Review your net monthly housing cost. The calculator subtracts net rental income from your mortgage payment. A result at or below $0 means your tenants are covering your housing cost entirely.

Who Is This For?

• First-time home buyers considering house hacking as an entry into real estate investing — wanting to see the actual numbers before committing to a multi-unit purchase.
• People trying to reduce their housing cost in expensive cities, comparing what they'd pay in rent vs. what they'd net after house hacking a duplex or triplex.
• Anyone who wants to model whether a specific property at a specific purchase price makes house hacking financially viable before making an offer.

Key Benefits

• Privacy first. All calculations run in your browser. Your mortgage figures and rental income estimates are never sent to a server.
• Completely free. No subscription, no paywall, no account required.
• No account needed. Works instantly — no sign-up to run your analysis.
• Accounts for real-world vacancy and maintenance. Unlike a simple rent-minus-mortgage estimate, this calculator builds in the reserves that separate profitable house hackers from those who get caught off guard by a vacancy or repair bill.

Common Use Cases

A buyer in a high-cost city can't afford a single-family home but finds a duplex within budget. They model the rental income from the second unit with 8% vacancy and 12% maintenance reserves. The result: their effective monthly housing cost drops from $2,800 to $900 — cheaper than their current rent.

A first-time investor uses FHA financing (3.5% down) on a triplex. They model all three units: their own unit costs them nothing, and the two rental units generate enough net income to cover the full PITI with a small monthly surplus.

Someone weighing rent vs. house hacking uses the calculator to compare: $2,200/month in rent vs. owning a duplex with a $3,000 PITI and $1,400/month in net rental income — effectively paying $1,600/month to own an appreciating asset instead of $2,200 to rent.

3 Pro Tips for Successful House Hacking

1. Look for "by-the-room" opportunities. In expensive cities, renting out individual rooms in a large single-family home can generate more revenue than a traditional duplex arrangement.
2. Analyze the exit strategy before you buy. Use the Investment Property Calculator to see how the property performs as a fully rented investment once you move out of your unit.
3. Manage your own units at first. Learning to screen tenants and handle minor repairs early saves thousands in property management fees as your portfolio grows.

Frequently Asked Questions