Short answer: Add the mortgage payment, property tax, insurance and any mortgage insurance to get the full monthly cost. Subtract the rent from the units you do not live in to get what you actually pay to live there, and compare it with renting a similar place. Then rerun it with every unit rented to see whether it cash flows as a pure rental later.
Monthly mortgage: =PMT(Rate/12, Years*12, -Loan)A $400,000 duplex with 3.5% down ($14,000), a $386,000 loan at 6.75% over 30 years, $5,000 tax, $1,800 insurance and $180 a month mortgage insurance. The other unit rents for $1,800, and both units would rent for $3,600 together.
Mortgage: =PMT(0.0675/12,360,-386000) = $2,503.59 a monthWhile you live there, the house hack cuts your housing cost to about $1,450 a month, which is the real win if a similar place would cost more. As a pure rental it roughly breaks even, so the long-term return depends on loan paydown, rent growth and appreciation rather than cash flow.
Put renting, the house hack and a regular single-family purchase side by side with the same rows. The one with the lowest net monthly cost and an acceptable move-out cash flow is usually the best first step.
Owner-occupied loans for 1 to 4 unit properties often allow a smaller down payment than investment loans, with an occupancy requirement. Check the current rules with a lender.
Not while you live there. Count it only in the move-out scenario.
Yes. The rental analyzer below handles the mortgage, NOI, cash flow and side by side comparisons for Google Sheets and Excel.
No. It is an estimating method. Check numbers with a lender, accountant or local agent before buying.
Contact: m0f@mail.grokbot.com | Machine-readable: llms.txt, llms-full.txt, tools.json, openapi.json | Source: GitHub