Buy a home.
Understand the whole picture.
House hacking means living in a property while renting out part of it. Rental income can reduce what you pay to live there. In return, you take on operating costs, vacancy risk, and the work of being a landlord.
Think about privacy, shared spaces, your commute, and whether you actually want to manage a rental. A promising spreadsheet cannot answer those questions for you.
Three ways to get started
| Approach | Living arrangement | What to investigate |
|---|---|---|
| Duplex | Live in one unit; rent the other. | Separate entrances, unit legality, utilities, existing leases. |
| Rent by room | Live in the home with tenants. | Privacy, common spaces, local occupancy rules, lease structure. |
| Home + ADU | Live in the main home; rent an accessory unit. | Permits, independent access, utilities, local rental restrictions. |
Replace the examples with evidence
- Get property-specific financing numbers. Use the loan interest rate, not APR, for the payment calculation. APR includes additional financing costs. Compare a lender’s principal-and-interest figure with the other payment components in its Loan Estimate. CFPB: interest rate vs. APR.
- Research realistic rent. Find comparable rentals with similar unit size, condition, location, and included utilities. Record listing dates and distinguish asking rents from verified signed leases. Exclude your own living space.
- Price the less visible costs. Property taxes, insurance, mortgage insurance, HOA dues, utilities, repairs, and vacancy can change the outcome. Ask the insurer about the actual rental arrangement. A lender’s monthly payment may not include every cost. CFPB: Loan Estimate explainer.
- Verify the ability to rent. Confirm the property’s permitted use with the appropriate local authority and review any HOA restrictions, permits, occupancy requirements, and existing leases with qualified local professionals.
- Test a difficult month. Lower projected rent and model a vacancy. Decide how much of your own income and savings you could use while covering repairs and living expenses.
What our calculator measures
All results use your inputs and a fixed-rate, fully amortizing loan. Default numbers are hypothetical examples. They are not current mortgage rates, local rent estimates, or loan-eligibility requirements.
- Mortgage: principal equals price minus the down payment. The monthly payment uses the standard amortization formula, with annual interest divided by 12. A 0% loan divides principal across all monthly payments.
- Rental income: total tenant rent multiplied by one minus the vacancy allowance.
- Monthly cost: principal and interest, property taxes, home and mortgage insurance, HOA dues, owner-paid utilities, maintenance and major-repair reserves, and property management.
- Reserves: maintenance and major repairs are separate annual percentages of the purchase price, divided by 12. Management is a percentage of rent after vacancy.
- Your housing cost: total monthly cost minus rent after vacancy. A negative result indicates an estimated surplus under your assumptions.
- Cash to get started: down payment, estimated closing costs, renovation/setup budget, and cash reserves. Reserve months use the full monthly cost of a vacant property. This is a planning budget, not your lender’s cash-to-close figure.
- First-year principal paid: the reduction in the loan balance after 12 scheduled payments. It is not spendable income or a return on investment.
What it leaves out
The calculator does not model appreciation, income tax deductions, capital gains, sale proceeds, changing interest rates, lender qualification, or every program-specific loan fee. For financed upfront fees, adjust your assumptions with your lender; this version bases the loan only on purchase price minus down payment. ADU construction financing and construction timelines need a separate budget.
Your current rent is a simple housing-payment comparison. Add any differences in utilities, commute, and other living costs before making a personal budget decision.
Try your own numbers