Co-living and rent-by-the-room calculator

How this calculator works

This calculator compares two ways to rent the same house. For rent by the room, it multiplies rooms rented by rent per room, reduces that by your room vacancy share, and subtracts the added costs of renting rooms, such as utilities, internet and cleaning. For the whole house, it reduces the whole-house rent by its vacancy share. Each side then subtracts the same mortgage payment and other expenses to show monthly cash flow, the difference per month and the difference per year.

Assumptions: you enter your own mortgage payment, so there is no rate field here. Use the full payment from your Loan Estimate or from the mortgage payment calculator. Rents, vacancy and costs are held flat. Furnishing, turnover, and the extra time and wear of managing several tenants count only if you include them in added costs or other expenses. Local rules on occupancy, leases and permits are not checked.

When you finance a rental, a lender usually bases rental income on the market rent for the whole property, from an appraisal or a lease, not on room-by-room rents. For rental property loans, often called DSCR loans, the lender compares that rent with the full monthly payment, including taxes, insurance and HOA dues. Ask how your lender treats room rentals before you count on that income.

Example: enter 4 rooms at $900 each, $500 of added costs and $3,500 for the whole house. Then add your mortgage payment and other expenses to see which way leaves more each month.

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