Real Estate Investing Calculators

House hacking net cost.

House hacking means buying a property, living in part of it and renting out the rest to offset your housing costs. Enter the purchase, costs and expected rent below to see your total monthly cost, the share the rent covers and your net cost to live there. Runs in your browser; nothing is sent or stored.

Your numbers

Purchase price

Down payment

Mortgage interest rate

Amortization (years)

Rent collected per month (rooms or other units)

Vacancy allowance

Property tax per year

Insurance per year

Maintenance per month

Utilities per month

Other monthly costs (mortgage insurance, HOA)

What you pay in rent now (optional)

The mortgage payment is principal and interest only, with monthly compounding. Add any mortgage insurance premium under other monthly costs. Check local rules on renting rooms or units and on how rental income is taxed.

Result

Fill the form and press Calculate.

Not financial advice. This is an estimating tool built on the numbers you enter. Real estate returns depend on assumptions that can be wrong; check them with a lender, an accountant and local sources before you buy.

Worked example

A $450,000 property with 5% down has a $427,500.00 mortgage costing $2,702.09 a month. Adding tax, insurance, maintenance, utilities and $150 of other costs brings the total to $3,902.09. Renting out $2,000 a month with 5% vacancy brings in $1,900.00, covering 48.7% of costs, so your net cost is $2,002.09 a month ($24,025.09 a year). Versus $2,200 of rent now, that saves $197.91 a month.

How it works

Mortgage payment = amortized payment on price x (1 - down payment %) with monthly compounding. Total monthly cost = payment + property tax / 12 + insurance / 12 + maintenance + utilities + other. Rent after vacancy = rent x (1 - vacancy). Net cost = total cost - rent after vacancy. Saving = current rent - net cost. Principal repaid builds equity but is included in the cost here.

Sources and basis

BiggerPockets describes house hacking as buying a property and renting out portions of it to offset your mortgage and expenses, and lists approaches such as renting by the room.

House Hacking (BiggerPockets), opened 2026-10-08.

FAQ

What is house hacking?

Buying a property, living in part of it and renting out the rest (rooms, a basement suite or another unit) to offset what it costs you to live there.

How do you calculate the net cost of a house hack?

Total monthly housing cost minus rent collected after vacancy. In the example, $3,902.09 - $1,900.00 = $2,002.09.

Does the net cost include principal?

Yes. The mortgage payment includes principal, which you build as equity, so part of the net cost is you building equity rather than money spent.

How much rent do I need to live for free?

Enough that rent after vacancy equals your total monthly cost. In the example that is $3,902.09, or about $4,107.46 of rent before a 5% vacancy allowance.

Are there rules about renting out part of my home?

Yes. Zoning, lease and insurance rules, and the tax treatment of rental income, vary by place and by mortgage lender. Check them before you buy.