Housing

Rental Property House Hack Calculator

Calculate the net housing cost when you live in one unit and rent out others with FHA eligibility check.

Decision Summary

Net monthly housing cost

$1,423.12

Rental income offsets $1500/mo of your $2923.12/mo PITI.

Down payment below 20% typically requires mortgage insurance (PMI/MIP), adding to monthly cost.
FHA loans require as little as 3.5% down but mandate MIP for the life of the loan.
Gross rent multiplier above 20 suggests the property may be overpriced relative to rental income.

Scenario Comparison

The main answer and the most important supporting outputs in one glance.

Net monthly housing cost

$1,423.12

Loan amount

$386,000.00

Monthly PI

$2,439.78

Monthly PITI

$2,923.12

Key Metrics

Loan amount

$386,000.00

Monthly PI

$2,439.78

Monthly PITI

$2,923.12

Effective housing cost

$1,423.12

Gross rent multiplier

22.22

How to use it

Enter purchase price, down payment, mortgage rate, term, property taxes, insurance, maintenance, number of units, your unit's share of the property, rental income from other units, and vacancy rate. House hacking means you live in one unit and rent the others.
Read your net housing cost after rental income, cash-on-cash return, and the effective mortgage subsidy from tenants. If rental income covers 50%-80% of the total mortgage and expenses, you are living at a steep discount to market rent.
A house hack works financially when the rental income reliably covers enough of the carrying cost that your effective housing expense is well below renting an equivalent unit. If it only works at 100% occupancy with zero maintenance, the model is too fragile.
Stress-test with one unit vacant for 2 months per year and maintenance at 1%-2% of property value annually. Compare your effective housing cost against renting using the rent vs buy calculator, and check overall property returns with the cap rate calculator.
Re-run when rents change, a unit turns over, or interest rates move before purchase. Track effective monthly housing cost, occupancy rate, and cash-on-cash return.

AI Integrations

Contract, discovery endpoints, and developer notes for agent use.

Always available for agents

Tool contract JSON

https://aifinhub.io/contracts/rental-property-house-hack-calculator.json

Stable input and output contract for this exact tool.

Human review

People can use the browser page to sense-check outputs and charts, but agents should still execute against the contract and discovery endpoints.

/agent-tools.json - machine-readable tool index.
/llms.txt - human-readable model discovery guide.
/.well-known/webmcp.json - WebMCP capabilities manifest.
/.well-known/ai-plugin.json - plugin-style discovery manifest.

{
  "tool": "rental_property_house_hack",
  "purchase_price": 425000,
  "down_payment_percent": 5,
  "mortgage_rate_percent": 6.75,
  "rental_income_monthly": 2400,
  "total_units": 3,
  "property_tax_annual": 5200,
  "insurance_annual": 2100
}

Open tool contract JSON Open AI integrations guide

Expand developer notes

Agent playbook

Resolve Rental Property House Hack Calculator from /agent-tools.json and open its contract before execution.
Validate inputs against the contract schema instead of scraping labels from the page UI.
Open the browser page only when a person wants to review charts, assumptions, or related tools.

Agent FAQ

Should ChatGPT, Claude, or another agent click through the UI?

No. Start with /agent-tools.json, then follow the tool's contract URL. The page UI is for human review, not parameter discovery.

When do tools show Quick and Advanced?

Every tool opens in Quick Start first. Advanced Controls keeps the same scenario, reveals more assumptions or diagnostics, and every tool keeps AI integrations inline below the instructions.

When should an agent still open the browser page?

Open it when a human wants to sense-check the output, review the chart, or keep exploring related tools after the calculation finishes.

Questions people usually ask

What is house hacking?

House hacking means buying a multi-unit property (duplex, triplex, fourplex), living in one unit, and renting out the others. Rental income offsets or covers your mortgage, dramatically reducing your housing cost. FHA loans allow as little as 3.5% down on properties up to 4 units.

How does this calculator work?

It models the full economics: purchase price, mortgage payment, rental income from other units, vacancy rate, maintenance, insurance, property taxes, and property management costs. It shows your effective monthly housing cost and cash-on-cash return.

Can rental income really cover the entire mortgage?

In many markets, yes. A $400,000 duplex with a $2,500 mortgage where the other unit rents for $1,800 means you effectively pay $700/month for housing while building equity. In high-cost markets, full coverage is harder, but partial offset is still valuable.

When should I use this vs a standard rental property calculator?

Use this when you plan to live in one of the units. The economics differ from pure investment properties because you get owner-occupied financing (lower rates, lower down payment), and your personal housing cost reduction is part of the return equation.

Is my data stored?

No. All calculations happen in your browser. Nothing is stored or transmitted.