What the Bank Will Approve

Lenders ration mortgage size by debt-to-income ratio. The 28/36 rule — housing under 28% of gross income, all debts under 36% — is the classic benchmark. This mortgage affordability calculator applies both and converts them into a maximum loan.

Two Rules, Two Loans

The 28% front-end ratio caps the housing payment on its own; the 36% back-end ratio subtracts your existing debts first, leaving the remainder for housing. Whichever yields the smaller loan is your real ceiling — the calculator shows both paths and their loans.

Beyond the Ratios

Qualifying is not the same as comfortable. Property taxes, insurance, HOA fees, and repairs ride on top of the payment, and a 36% ratio leaves little margin for surprise expenses. Many buyers voluntarily cap their housing at 25–30% regardless of what a lender approves.