Free tools
Run the numbers on your first two-to-four-unit home
Twenty-eight calculators, grouped by the question you are trying to answer. Every one runs in your browser: no account, no report caps, no trial clock. Read the free-forever pledge.
The short answer
The Van to Vault tools page is a free library of house hacking and property investing calculators, covering deal analysis, cash-on-cash, cap rate, BRRRR, rent versus buy, debt-to-income, affordability, a readiness roadmap, and a long-term projection that models a property year by year over a 1-30 year hold. Every tool here is free forever: no signup, no report caps, no trial clocks.
Start here
Can I afford it?
- Debt-to-Income (DTI) CalculatorFront-end and back-end DTI, and what conventional and FHA lenders will approve.
- Mortgage CalculatorThe real monthly payment with taxes, insurance, PMI and HOA, at this week's 30-year average.
- Down Payment CalculatorHow many months of saving stand between you and the down payment.
- Down-Payment BudgetYour real monthly surplus, and the month you hit your down payment on a target price.
- Housing Path CheckA room, an ADU, a manufactured or tiny home, co-buying: what each path would cost you each month.
- Rent EstimateHUD’s FY2027 rent for any ZIP code by bedroom count, nearby ZIP codes on a map, and your own comps.
- Down Payment Assistance LookupCan a metro's down payment help be used on a 2-4 unit home you live in? Each answer links the program's own source.
- Move-Out Cost CalculatorMove-in cash plus a safety cushion, and how long it takes to save it.
- Cost of Living ComparisonTwo cities on rent, costs and pay: does a move leave you ahead?
Is this deal any good?
- Deal ScreenerThe 1% rule, the 50% rule, cap rate and cash-on-cash on one page.
- Cap Rate CalculatorNOI over price, from price, rent and operating costs.
- Cash-on-Cash CalculatorAnnual cash flow over cash invested: the return that hits your bank account.
- 1% Rule CalculatorDoes monthly rent clear 1% of the price? The fastest first screen.
- 50% Rule CalculatorAssume half the rent goes to expenses; see what is left for the mortgage.
- Rent Comp WorksheetEstimate market rent like an appraiser: pick comps, adjust, land on a number.
Plan the long game
- Long-Term ProjectionA property year by year over a 1-30 year hold: rent growth, amortization, time.
- Sell vs. Keep CalculatorSell, keep as a rental, or sell to fund your next house hack: three paths compared.
- FIRE ProjectorWhen rental cash flow plus savings covers your expenses, charted.
- Airbnb CalculatorShort-term against long-term rent, and the occupancy where they break even.
Renovate and flip
- BRRRR CalculatorBuy, rehab, rent, refinance: cash left in, equity created, post-refi cash flow.
- Rehab Cost EstimatorA line-item renovation budget with contingency and cost per square foot.
- 70% Rule CalculatorMax offer: 70% of ARV minus rehab. Know your ceiling before you bid.
- Fix and Flip CalculatorPurchase, rehab and ARV in; profit, cash-on-cash and the 70% check out.
- Wholesaling CalculatorMaximum allowable offer, contract price, assignment fee and the buyer's margin.
Questions people ask about these calculators
Are these calculators actually free?
Every calculator on this page is free to use with no account and no usage limit. There is a written free-forever pledge covering that, because the usual pattern in this category is a tool that works twice and then asks for a card.
Which calculator should I start with?
Start with the house hacking calculator if you are weighing a two to four unit building you would live in, or the rent versus buy calculator if you are still deciding whether to buy at all. The quick screens are for filtering listings once you know what you are looking for.
Can I put these calculators on my own site?
Several of them can be embedded with one block of HTML, free, with an attribution link. The embed page lists which ones and gives you the code.
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Sources
- [S1] Van to Vault, read 24 September 2026: “Fannie Mae's Selling Guide caps manually underwritten loans at 36% total, allows up to 45% when the borrower meets credit score and reserve requirements, and allows up to 50% for loans run through Desktop Underwriter.” vantovault.com.