House Hacking Calculator
What would you pay each month to live in one unit and rent out the others? Estimate your cost after tenant rent, vacancy, your utilities and modeled maintenance reserves. Start with a duplex, triplex or fourplex, then replace the example inputs with your numbers.
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Start with the location
Pick the market and we fill local property tax and insurance rates for you.
Your Monthly Cost
After rent, reserves & utilities
/month
Includes your utilities and modeled maintenance reserve. Budget rental-side costs separately.
See included costs
Includes the loan payment, taxes, insurance, HOA, your utility share and your occupied unit's square-footage share of repair and capital-replacement reserves. Excludes the rental share of those reserves, management, turnover, utilities outside your share and cash to buy the property. Amounts are rounded after calculation.
Check the vacancy risk
Each additional percentage point of vacancy adds about $14/month to your cost, holding other inputs fixed. An empty unit can still mean a month with no rent.
Rent after vacancy as a share of the payment, taxes, insurance and HOA. Excludes utilities and reserves.
Paying $8,035/year more than renting
DTI: 40.3% (modeled max 43.0%). Lender review required.
For landlords
Do you accept Section 8?
List your rental free on VoucherMatch and reach voucher holders searching your market. Every application shows the voucher type and household size up front.
How to calculate your house hacking cost
Choose the unit you will occupy and enter rent only for spaces you can actually lease. Replace the example loan terms, taxes and insurance with property-specific estimates. The main result follows this calculation:
Monthly housing cost = loan payment, taxes, insurance and HOA + your modeled maintenance reserve + your utility share − tenant rent after vacancy.
The maintenance reserve here is your occupied unit's square-footage share of repairs and capital-replacement allowances applied to tenant rent plus your unit's market rent. The housing-cost result does not add the rental share of those reserves, management fees, turnover costs or landlord-paid utilities outside your entered share. Budget for those separately before treating the result as affordable.
Use your lender's Loan Estimate to check loan payments and closing costs. A qualification screen is separate from your monthly budget; it is not an approval or a promise that rent will cover the payment.
Worked example: a $400,000 duplex
This illustration uses the calculator's starting duplex, with one owner unit and one tenant paying $1,400 per month. It stays fixed while you edit your own deal above. The example rate and mortgage-insurance inputs are illustrative, not a quote or current program guidance.
Inputs to reproduce this example
- FHA financing: 3.50% down, 7.00% interest, 30 years.
- Upfront mortgage-insurance input: 1.75%, financed; annual mortgage-insurance input: 0.85%.
- Property taxes: $5,000/year; insurance: $2,000/year; HOA: $0/month.
- Vacancy: 5.0% of tenant rent. Repairs: 5.0%; capital replacements: 5.0%.
- Owner unit market rent: $1,400/month. Owner unit: 900 square feet of 2,400 total.
- Owner utility share: 50.0% of $440/month, or $220.
- Closing-cost input: 3.0%; loan points: 0. Current rent for comparison: $1,800/month.
| Budget item | Monthly amount |
|---|---|
| Principal and interest on $392,755 financed | $2,613 |
| Property taxes | $417 |
| Homeowners insurance | $167 |
| Mortgage insurance | $278 |
| HOA | $0 |
| Your modeled maintenance reserve | $105 |
| Your utility share | $220 |
| Less tenant rent after $70 vacancy allowance | −$1,330 |
| Estimated monthly housing cost | $2,470 |
Totals are calculated before rounding. Estimated purchase cash is $26,000: $14,000 down plus $12,000 closing costs. That is separate from a repair and vacancy fund. The financed upfront premium of $6,755 increases the loan balance.
What if vacancy rises?
Raising vacancy from 5.0% to 10.0% reduces effective rent by $70 per month. With the other inputs unchanged, housing cost rises to $2,540 per month. A vacancy allowance spreads expected lost rent across the year; an empty unit can still mean a month with no rent at all. Check that you can carry the payment during that gap.
Compare the property you will actually live in
- Duplex: enter rent from one tenant unit and keep your occupied unit separate.
- Triplex or fourplex: enter each tenant unit's rent and compare the cost and vacancy exposure, not just total rent.
- Rented rooms or an ADU: use the matching property type, check the rentable spaces, and review who pays the shared utilities.
For the purchase process and financing questions, read the first-time house hacking walkthrough. Compare layouts in the duplex versus triplex guide, or research tenant rents with local rent estimates. If you plan to rent every unit from day one, use the multifamily rental calculator.
House hack guides by market
Frequently asked questions
Does rent from the unit I live in count as income?
Not in your owner-occupied housing cost. Only the units or rooms you rent to others supply tenant income. Your own unit's market rent can still affect the modeled maintenance allocation and move-out analysis, so keep that estimate realistic.
Can I compare a duplex, triplex and fourplex house hack?
Yes. Choose the property type, identify your occupied unit, and enter the rent for each tenant unit. Compare the monthly cost including utilities and modeled reserves, then increase vacancy to see how much income risk you can carry. More units do not automatically mean a lower cost.
Does a negative housing cost mean I can live for free?
It means rent after the vacancy allowance exceeds the costs included in this estimate. It is a modeled surplus, not a guarantee. Budget separately for rental-side expenses omitted from the housing-cost result, unexpected repairs, turnover and cash needed to buy the property.
Does the calculator tell me whether I qualify for an FHA or VA loan?
It provides a planning estimate from your inputs, not a mortgage approval. Confirm the property configuration, eligible rental income, loan terms, mortgage insurance and required reserves with your lender. The amount you can borrow and the amount you can afford to pay each month are separate questions.
Is the calculator free?
Yes. Unlimited property analysis without an account: full results, all charts, sensitivity testing, 30-year projections, and recommendations. Create a free account to save a deal. Pro adds professional financing models, portfolio management, unlimited saved deals, and report exports.