A Free DealCheck Alternative for House Hacking

People ask me which app to use to run numbers on a duplex, and DealCheck is the name that comes up most often. It is a good tool for landlords. It is not built for the way I bought my first building, so this post covers both: what DealCheck does well, and a free alternative for the specific case of buying a small multifamily and living in it.

What DealCheck does well

DealCheck is a general-purpose deal analyzer for rental properties, flips, and BRRRR projects. It has native iPhone and Android apps, it can pull a property’s details from public records so you type less, it looks up sales and rental comps, and it produces PDF reports you can hand to a lender or a partner. The free plan stores up to 15 properties; the paid plans were $10 and $20 per month when I checked their pricing page in July 2026.

For an investor comparing rentals over a year of shopping, that is a sensible toolkit, and I would not talk anyone out of it for that job.

Where it fits house hacking poorly

DealCheck models a property as something you buy and rent out entirely. House hacking is a different situation. You buy a duplex, triplex, or fourplex, live in one unit, and rent the others, which makes the deciding questions different too:

• What do I actually pay each month to live here, once the other unit’s rent comes in?
• How does the picture change later, when I move out and every unit rents?
• What does an FHA loan with 3.5% down do to the payment and the cash needed at closing?

You can bend DealCheck toward those answers by editing its rent roll by hand and interpreting outputs that were designed for a pure rental. As of July 2026, though, I could not find an owner-occupied mode anywhere in the product: no way to mark a unit as the one you live in, no split between the years you live there and the years after, and no output for your own monthly cost of living. Their marketing mentions house hacking; the workflow stays investor-shaped.

The free alternative I built

The VanToVault House Hacking Calculator runs in the browser, is free, and asks for no account. It was built around the owner-occupied questions:

• Effective housing cost. Your full payment (principal, interest, taxes, insurance, mortgage insurance) minus the rent from the other units, plus a repair and vacancy reserve. This is the number to compare against your current rent.
• Two phases, computed separately. Cash flow while you live in one unit, and cash flow after you move out and rent your unit too.
• An FHA preset. One click sets 3.5% down, the minimum for an owner-occupied 1-4 unit FHA purchase.
• Typical rents built in. If you do not know what the other unit could rent for, the calculator shows HUD FY2026 Fair Market Rents for twelve metros where the house-hack math tends to work, with one click to use the number.
• Sharing without an account. A link that reproduces your exact numbers, and a print view for saving as PDF.

As a concrete example: on a $240,000 duplex with 5% down at 6.55% interest and the other unit renting for $1,350, the calculator shows an effective housing cost of about $665 a month. That single figure, next to whatever you pay in rent today, is most of the buying decision.

Which one to pick

If you are building a rental portfolio and want saved deals, comps, and polished exports, DealCheck earns its subscription. If the question in front of you is whether a duplex can lower your cost of living, that is the exact question the free calculator answers, and checking costs nothing. The own-for-less analysis covers which metros the numbers currently favor.

Somewhere in the middle of a duplex decision and want a second set of eyes on your numbers? Send them over.