House Hacking Calculator

Last updated: May 2026

See how much rental income from your property can offset your mortgage payment.

Your Property

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Rental Income

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Results

Total Monthly Payment
PITI + maintenance
Rental Income
after vacancy
Your Net Cost
monthly out of pocket
% Offset
covered by renters
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House hacking means buying a property, living in one unit or room, and renting out the rest to offset your housing costs. Common strategies include duplex/triplex/fourplex purchases, renting basement or ADU units, or renting rooms in a single-family home.

FHA loans allow 3.5% down on 2–4 unit properties if you live in one unit, making this a common entry strategy for first-time real estate investors.

Net cost = Total PITI + maintenance − rental income after vacancy. A negative net cost means your renters are covering more than your full payment.

⚠️ Results are estimates. Does not include income tax on rental income, landlord insurance, capital expenditures, or property management costs. Consult a tax advisor and real estate professional.

House Hacking: Using Rental Income to Offset Your Mortgage

House hacking is a real estate strategy where you purchase a property, live in part of it, and rent out the remaining units or rooms to offset — or eliminate — your monthly housing cost. The concept is simple but the financial impact is significant: instead of paying $2,000/month in rent or mortgage with no return, you leverage other people's rent to cover most or all of that expense while building equity in an asset you own. The strategy is especially powerful for first-time buyers because owner-occupant financing (FHA, conventional, VA) comes with lower down payment requirements and better interest rates than investment property loans.

The most common entry point is a 2–4 unit multifamily property purchased with an FHA loan at 3.5% down. The buyer occupies one unit and rents the others. HUD allows rental income from the other units to count toward mortgage qualification, which means a house hack can let you buy a property you otherwise couldn't afford. Over time, many investors use their first house hack as a launching pad — after a year of owner-occupancy, they move out, convert it to a full rental, and repeat with another property.

StrategyProperty TypeHow It WorksTypical Monthly Savings
Traditional hackDuplex/triplexLive in one unit, rent others$800–$2,000/mo offset
ADU hackSFH + ADURent accessory dwelling unit$1,000–$1,800/mo
Room rentalSingle-family homeRent spare bedrooms$400–$1,200/mo
Short-term roomsSingle-family homeAirbnb spare rooms$600–$2,000/mo
FHA hack2–4 unit multifamily3.5% down + rent incomeMinimal/no mortgage payment
Live-in flipFixer-upperRenovate then sellEquity gain vs monthly savings

Worked Examples

Example 1 — FHA Duplex Purchase
A buyer purchases a duplex for $380,000 using an FHA loan with 3.5% down ($13,300 down payment). Monthly mortgage payment including taxes and insurance: $2,150. The lower unit rents for $1,400/month. Net housing cost after rental income: $750/month. Compared to the local market rent of $1,800/month for a comparable unit, the house hacker saves $1,050/month ($12,600/year). Over 5 years, that's $63,000 in housing cost savings plus equity growth on a $380,000 asset.
Example 2 — Spare Bedroom Strategy
Owner of a single-family home with two spare bedrooms rents each room to a housemate at $700/month → $1,400/month total rental income. The owner's mortgage is $2,400/month. Effective housing cost after room income: $1,000/month — a 58% reduction in carrying cost. At an average market rent of $1,900/month for a comparable standalone unit, the strategy saves $900/month, or $10,800/year, with no additional down payment or purchase required.

Frequently Asked Questions

What is house hacking?

House hacking is the practice of buying a property, living in part of it, and renting out the rest to reduce or eliminate your housing costs. It can involve a multifamily building, a single-family home with an ADU, or simply renting spare bedrooms. The strategy combines the benefits of homeownership (equity, appreciation, leverage) with rental income that offsets the mortgage.

Can you house hack with an FHA loan?

Yes. FHA loans allow owner-occupants to purchase 2–4 unit multifamily properties with as little as 3.5% down. The owner must occupy one unit as their primary residence. FHA lenders can count a portion of the expected rental income from other units toward your qualifying income, making it easier to afford a multifamily property than a standard single-family purchase at the same price.

Does renting rooms affect your mortgage?

Renting rooms in your owner-occupied home generally does not affect an existing mortgage — you're not violating any typical loan terms by renting part of your primary residence. However, your homeowner's insurance policy may need to be updated to cover rental activity, and some HOA agreements restrict rentals. Always review your loan documents and local ordinances before renting.

What are the tax implications of house hacking?

Rental income from house hacking is taxable. However, you can deduct a proportional share of expenses (mortgage interest, taxes, insurance, maintenance, depreciation) attributable to the rented portion. If you rent out 40% of your home's square footage, approximately 40% of shared expenses may be deductible. A tax professional can help you maximize deductions while staying compliant.

Is house hacking legal everywhere?

House hacking itself is legal in most jurisdictions, but local zoning, HOA rules, and short-term rental regulations can restrict how you implement it. Renting rooms in most single-family zones is generally permitted; short-term rentals (Airbnb) have more varied restrictions. Always check your city's zoning code, HOA covenants, and state landlord-tenant laws before proceeding.