A mortgage pre-approval letter states the maximum a bank will lend — not the amount that fits comfortably into a monthly budget. Those two numbers are often different, and the gap between them is where a lot of homebuyers end up house-poor.
Why the pre-approval number runs high
Lenders calculate a maximum loan based on debt-to-income ratios that assume a fairly high share of monthly income going toward housing — commonly up to around 28-36% of gross income, depending on other debts. That's a ceiling the bank is comfortable lending up to, not a recommendation for how much of a paycheck should actually go to housing every month.
What actually makes up the monthly payment
The loan principal and interest are just one piece. Property taxes, homeowners insurance, and — if the down payment is under 20% — private mortgage insurance (PMI) all add to the real monthly cost, and HOA fees stack on top of that in many communities. A payment estimate that only covers principal and interest can understate the real monthly cost by a significant margin.
Getting a realistic number
- Open the Mortgage Calculator.
- Enter the home price, down payment, interest rate, and loan term.
- Add estimated property taxes, insurance, and HOA fees to see the full monthly payment, not just principal and interest.
A sanity check beyond the calculator
Once the full monthly payment is known, comparing it against take-home pay (not gross income) gives a more honest read on affordability than the bank's pre-approval ceiling — a payment that's technically approved can still leave uncomfortably little room for everything else a monthly budget has to cover.