Best for
Owner-occupied duplex and small multifamily buyers
Buyers considering roommates or rentable space
First-time investors using owner-occupied financing
Back to calculators resources
Calculator
Run the numbers before you call it a house hack.
This spreadsheet helps buyers compare the home they will live in now with the rental it may become later.
What's inside
Purchase price, down payment, and loan inputs
Rent and expense assumptions
Monthly cost while you live there
Cash flow view after you move out
Use it when
Run it before touring a likely house hack.
Compare two properties with different rent potential.
Use it with the house hack guide.
The right house hack has two jobs
It needs to work as your home and as a future asset. This calculator keeps both views in front of you, so comfort, cash flow, and exit strategy do not get separated.
Do not trust rent guesses
The model is only as useful as the rent assumptions inside it. Pull real comps, ask about tenant demand, and leave room for vacancy and repairs.
Frequently asked questions
House Hack Calculator FAQ
Short answers to common questions that come up before you use this resource or bring the next decision to Roots.
How do I calculate if a house hack will work?
Add up your total monthly payment including principal, interest, taxes, insurance, and any mortgage insurance, then subtract the rent the other units or rooms will bring in. The result is your real out-of-pocket housing cost. A house hack calculator also shows the cash flow once you move out and rent the whole property.
How much can a house hack lower my mortgage payment?
It depends on rent and the number of rentable units or rooms, but many house hackers cut their effective housing cost by half or more, and some cover the entire payment. The honest number comes from real rent comps for your specific property, not optimistic estimates.
What is break-even on a house hack down payment?
Break-even is the point where the money you have saved on housing costs equals the cash you put into the deal, mainly the down payment and closing costs. Tracking it tells you how quickly the house hack has effectively paid for itself, which is a useful way to compare two properties.
Will my house hack cash flow after I move out?
It can, if total rent from all units covers the mortgage, taxes, insurance, maintenance, vacancy, and management with room to spare. A property that breaks even while you live there does not automatically cash flow once vacant, so model both scenarios before you buy.
Keep going
Related Roots resources.
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