House Hacking Calculator

House hacking is the fastest way for a first-time buyer to build real estate equity. This calculator models your net housing cost after tenant rent — often negative in duplexes through fourplexes at today's rents.

Purchase price

Down payment %

FHA allows 3.5%

Mortgage rate

Full monthly PITIA

Total units

Units you'll rent out

Average rent per unit

Vacancy %

Your monthly housing cost

$413

after tenant rent

Effective rent collected

$3,487

Tenant % of housing

89.42%

how much tenants cover

Annual savings vs $2,500 rent

$25,050

How the math works

House hacking means buying a multi-unit property, living in one unit, and renting the others. FHA and conventional low-down-payment loans apply because it's owner-occupied. Tenants effectively pay down your mortgage while you live nearly free.

Scale options: duplex → triplex → fourplex (max FHA owner-occupied). Rent-by-room on a single family house also works. After a year of owner occupancy, you can move out and keep the property as a pure rental, then repeat the process — the classic "BRRRR + house hack" ladder.

How to Use

Enter purchase price, down payment %, rate — FHA allows 3.5% down on owner-occupied properties up to 4 units.
Enter full monthly PITIA (principal + interest + tax + insurance + HOA/association).
Enter total units and units you'll rent out.
Enter average rent per unit and vacancy assumption.

Frequently Asked Questions

Can I use FHA for a fourplex?

Yes — FHA allows 3.5% down on 1–4 unit owner-occupied properties with self-sufficiency ratios. VA allows 0% down. Conventional allows 5-15% down depending on units. All require you live in one unit for at least one year.

Can I count tenant rent toward qualifying?

Yes, on 2–4 unit properties. FHA and conventional allow 75% of market rent on vacant units and 75% of lease-documented rent on occupied units to count toward your debt-to-income ratio. This significantly expands buying power.

What about a rent-by-room single family?

Works too — same math, different structure. Single-family owner-occupied plus renting rooms has fewer regulatory hoops than multi-unit but typically fewer rooms to rent (1–3 vs 3 in a fourplex).

When can I move out?

FHA requires 12 months owner occupancy. After that, you can move out, refinance to non-owner-occupied (if needed), and keep the property as a rental. Repeat the process on a new property — rinse and repeat for portfolio building.