House Hack Calculator

A house hack is a property you live in that also pays for itself. You buy a duplex, triplex, or fourplex, occupy one unit, and rent the others — or you buy a single-family home and rent out spare bedrooms. Your tenants' rent offsets the mortgage and operating costs, so the question isn't “what's my return?” but “what do I actually pay each month to live here?” That number is your total mortgage payment plus operating expenses, minus the rent your tenants pay. If it lands at or below zero, you live for free.

The low down payment is the whole point. A pure investment property is a non-owner-occupied loan, and lenders price it accordingly — you need a large down payment and you get no low-down insured option. But because you live in a house hack, it's an owner-occupied purchase. FHA financing allows as little as 3.5% down; owner-occupied conventional can go to about 5%. Same building, same rent roll, a fraction of the cash. That single distinction is why house hacking is one of the few realistic entry points into rental property for someone without a large pile of savings.

Your unit isn't a rental — so don't treat it like one. This is where popular calculators quietly distort the numbers. Your own unit produces no rent, so it must be excluded from income entirely. Just as importantly, it must not have a vacancy allowance applied to it: vacancy is a haircut on rent you expected to collect, and you were never collecting rent from yourself. Counting phantom rent on your unit inflates your income; applying vacancy to it invents a loss on income that never existed. Both errors skew the result, sometimes in opposite directions, which makes them hard to spot. This calculator counts rent only from the units you let out, and applies your vacancy percentage only to those units.

What happens when you move out. The house hack has a second act. Once you leave, every unit can be rented, so gross rent jumps and the property becomes a conventional rental — with vacancy now correctly applied across all units. You keep the owner-occupied loan you originally qualified for, which is why this strategy compounds so well. The calculator shows that fully-rented scenario next to your live-in numbers. From there, run the deal through the cash-on-cash return calculator or the rental property ROI calculator to see how it performs as a pure investment.

The honest downsides. You live next to your tenants. You hear their music, you share walls and often a yard or laundry, and you are the person they call at 11pm when a pipe goes. That is not passive income — it's a job with a discount attached. Owner-occupancy loan programs also typically require you to live in the property for around a year before moving out, so read your loan terms rather than assuming you can leave whenever you like. Small multifamily inventory is thinner and can be harder to finance than a plain single-family home. And the leverage that makes the low down payment attractive cuts both ways: with little equity, a non-paying tenant hits your own housing budget directly, not some abstract return figure. House hacking works well — but it works because you show up.