What is house hacking? You buy a home, live in part of it and rent out the rest, so tenants cover some of your housing cost. It is usually a duplex, triplex or fourplex, though a spare room or accessory unit counts. FHA loans require you to move in within 60 days. Test your numbers below.
House hacking calculator
Enter a price, loan, costs and rent. The tool works out the monthly payment, your net housing cost, what renting would cost instead, and how many months of savings it takes to recover the down payment. The rate is editable and the table shows what a move does to the result.
House hacking calculator
Your net housing cost is $1,864 a month, which is $136 a month less than the $2,000 rent you entered. This compares monthly cash only. It leaves out closing costs, repairs beyond your maintenance figure, tax effects and any change in the home's value.
The FHA self-sufficiency test applies to three- and four-unit properties, so it does not apply at this unit count.
The same deal at other rates
| Rate | Principal and interest | Net housing cost | Against renting |
|---|---|---|---|
| 6.24% | $2,416 | $1,603 | $397 |
| 6.74% | $2,545 | $1,732 | $268 |
| 7.24% | $2,677 | $1,864 | $136 |
| 7.74% | $2,811 | $1,998 | $2 |
| 8.24% | $2,948 | $2,135 | -$135 |
Runs in your browser. Nothing is stored or sent. The 7.24% rate is the Freddie Mac 30-year average for October 29, 2026, not a quote, so type your own. The 1.75% and 0.55% premiums are FHA figures for a loan with more than 95% loan to value over 15 years and at or under $726,200; set both to 0 for a loan without them. Price, taxes, insurance, maintenance, rents and vacancy are editable assumptions. This compares numbers only and is not advice to purchase anything.
Key takeaways
- On the example $400,000 duplex with 3.5% down at 7.24%, costs run about $3,704 a month and rent brings in $1,840, for a net housing cost of about $1,864.
- Against $2,000 in rent, that saves $136 a month, so the $14,000 down payment takes about 103 months to recover from savings alone.
- FHA requires at least one borrower to occupy within 60 days of signing and intend to stay at least one year, per HUD Handbook 4000.1, read November 2026.
- FHA three- and four-unit properties face a self-sufficiency test: rents less at least 25 percent must cover the full mortgage payment.
| Setup | What you rent | FHA detail to know | Main trade-off |
|---|---|---|---|
| Duplex | The other unit | No self-sufficiency test | One tenant leaving takes all of the rent |
| Triplex or fourplex | Two or three units | Self-sufficiency test, 3 months of reserves | Higher price, more tenants, harder test |
| One unit with an ADU | The accessory unit | Stays a one-unit property; 2 months of reserves if rent is used to qualify | Smaller rent, tenant close by |
| Rooms in your home | Bedrooms | Ask your lender how room rent is treated | You share the kitchen |
How does house hacking work?
House hacking works by moving part of your housing cost onto a tenant. You borrow on owner-occupied terms, live on the property, and put the rent toward the payment. The result is usually a lower housing bill, not free housing. How much lower depends almost entirely on the rate, the price and the rent.
The word gets stretched. People also use it for a roommate or a garage rental, and they are not wrong. Most of the math below assumes separate units, because those are the ones with separate rent, and the ones FHA counts as units.
House hacking a duplex: the worked example
House hacking a duplex means your neighbor pays part of your mortgage. In the calculator's example, you buy a 400,000 dollar duplex with 3.5 percent down, or 14,000 dollars. The price, rents and costs here are assumptions, and the rate is the Freddie Mac 30-year average of 7.24 percent on October 29, 2026. It is not a quote, and FHA pricing differs.
The financed loan is 392,755 dollars, including the upfront premium. Principal and interest come to about 2,677 dollars. Add 177 dollars of monthly mortgage insurance, 400 of taxes, 150 of insurance and 300 of maintenance, and you reach about 3,704 dollars. The other unit rents for 2,000 dollars, or 1,840 after an 8 percent vacancy allowance. Your net cost is about 1,864 dollars.
The formula in plain words
The payment uses the standard amortization formula: loan times the monthly rate times growth, divided by growth minus one, where growth is one plus the monthly rate, raised to the number of payments. Net housing cost is the payment plus taxes, insurance, mortgage insurance and maintenance, minus rent collected. Months to recover is the down payment divided by monthly savings against renting.
Rate matters more than most people expect. At 8.24 percent the same deal costs 135 dollars a month more than renting. At 6.24 percent it saves about 397. Those are one point apart in each direction. The rate table in the tool shows the steps, and it is the first thing to rerun when your lender gives you a real quote.
FHA owner-occupancy rules for house hacking
FHA lets you house hack because it insures loans on properties of up to four units when you live in one. The rule is occupancy. All of this comes from HUD Handbook 4000.1, Update 18, which we read in November 2026. Your lender may add stricter rules, so confirm the details with them.
- Move-in. At least one borrower must occupy within 60 days of signing the security instrument and intend to continue for at least one year. 203(k) products may differ.
- What counts as a residence. A principal residence is where you live for the majority of the calendar year, and you can have only one at a time.
- Not a route to rentals. FHA will generally not insure more than one property as a principal residence for a borrower, and it will not insure a loan designed to use FHA insurance to obtain investment properties. There are exceptions, which your lender can explain.
- Down payment. The minimum investment is 3.5 percent. A credit score of 580 or above is eligible for maximum financing, and 500 to 579 is limited to 90 percent loan to value.
- Mortgage insurance. The upfront premium is 1.75 percent of the base loan. The annual premium is 0.55 percent for the life of the loan when loan to value is above 95 percent, the term is over 15 years and the base loan is at or under 726,200 dollars.
The self-sufficiency test on three and four units
For three- and four-unit properties, the mortgage payment divided by net rental income may not exceed 100 percent. Net rental income uses the appraiser's fair market rent for all units, including yours, less the greater of the appraiser's vacancy and maintenance estimate or 25 percent. You also need three months of payments in reserve after closing.
Set the calculator to three or four units and it estimates this ratio from your rents. The appraiser's numbers decide the real one, which is why a fourplex that looks fine on a listing sheet can still fail. For an early rent check, HUD publishes Fair Market Rents by area, which are 40th percentile figures and not an appraisal.
Is house hacking worth it?
House hacking is worth it only if the numbers and the arrangement both suit you, and we cannot tell you that from here. The calculator compares monthly cash. It shows one side of the ledger and leaves the rest out on purpose: closing costs, a roof, your time and whether the home gains or loses value.
The example also repays about 3,809 dollars of principal in year one, which the 103 months ignore. Renting has no equivalent, and it also has no furnace. If the other unit sits empty, your bill goes from 1,864 to 3,704 dollars a month, so look at that cell before you look at the savings. To compare the property with a pure rental, run it through our cap rate calculator. For the wider setup, see how to start a rental property business. This is general education, so check your own plan with an advisor.
Taxes on the rented part
Rent is taxable income, and shared expenses get split. IRS Publication 527, for 2025 returns and read November 2026, lets you divide them by any reasonable method, with rooms or square footage most common. Its example rents a 180 square foot room in an 1,800 square foot house, so 10 percent of a shared expense counts as rental. A tax professional can apply it to your duplex.
Being a landlord through a shared wall
Your tenant knows which door is yours. That changes the job. There is no property manager in between, and "I will call you back" is harder to say to someone who can see your car in the driveway. Before move-in, you still need a lease, screening and a repair process. Our guide on how to be a landlord covers those.
Vacancy is the part you can affect. On the example, an empty month costs you 2,000 dollars, or about 15 months of the savings in the calculator. Renters calling about your listing often reach you at work. Whether you need help with that depends on scale.
On a duplex, you probably do not. A voicemail and quick callbacks will cover one unit that turns over once in a while. callflo.ai starts to make sense when you hold several units or a day job keeps you off the phone. It is an AI receptionist that answers your rental line around the clock, answers questions from what you give it and captures leads. On VIP it also books tours on your calendar. Starter is 39 dollars a month on annual billing or 49 dollars month to month, with 120 minutes. The page for investors and landlords shows how it works, and pricing has the plans.
Hear what would answer your rental line
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