The number your lender approves you for is not the number you should spend. That preapproval letter is a maximum, not a recommendation. It says what a bank is willing to risk based on your income, debts, and credit score. It doesn’t know about daycare, student loans, car repairs, or the fact that you’d like to retire before you’re seventy. If you treat the maximum as your budget, you’ll be house poor. You’ll own a nice place and stress about every other bill. That’s junk credit waiting to happen. So let’s do the math lenders don’t do for you.
Start with your take-home pay, not gross. Gross is a fantasy number before taxes, health insurance, 401(k), and all the other deductions that keep your paycheck smaller than you expect. Add up what actually hits your bank account each month. If your pay varies, use a conservative average from the last year. Then subtract your fixed obligations. Rent, utilities, minimum debt payments, groceries, gas, phone, insurance, childcare, and any regular savings you refuse to skip. What’s left is your housing ceiling. Not what’s left after you buy the house and hope for the best.
A common rule is the 28/36 rule. Your mortgage payment, including principal, interest, property taxes, and homeowners insurance, should stay under 28 percent of your gross monthly income. Your total debt payments, including that mortgage, should stay under 36 percent. But rules like that are training wheels. In expensive cities or with high debt, even 28 percent can feel tight. In cheaper areas with no debt, you might handle more. The rule isn’t magic. It’s a starting point. Your actual life is the final judge.
Don’t forget the costs that don’t show up in the mortgage calculator. Principal and interest are only part of the payment. Property taxes can jump after a sale, especially if the previous owner had a homestead exemption you don’t qualify for. Homeowners insurance is rising in many states, and in some places you also need flood or wind coverage. If your down payment is less than twenty percent, expect private mortgage insurance. If you buy in a neighborhood with an HOA, add those dues. They can be small, or they can feel like a second car payment. Then add maintenance. A good rule is to set aside one percent of the home’s value each year for repairs and upkeep. On a three-hundred-thousand-dollar house, that’s three thousand dollars a year, or two hundred fifty a month. That’s real money.
Your down payment matters, but it isn’t everything. Twenty percent avoids PMI and gives you instant equity, but waiting forever to save it can cost you too. In a market where rents and prices rise, buying earlier with a smaller down payment can make sense if the monthly payment is truly manageable. Just run the numbers with PMI included. Also remember closing costs. They usually run two to five percent of the loan amount. On a three-hundred-thousand-dollar loan, that’s six thousand to fifteen thousand dollars. You need that cash on top of your down payment. If it drains your emergency fund, you’re one broken furnace away from credit card debt.
Your credit score directly affects your mortgage rate. A difference of one percentage point on a three-hundred-thousand-dollar loan can cost tens of thousands over thirty years. Before you shop for houses, check your credit reports for errors. Pay down revolving balances. Don’t open new credit cards or finance a car right before applying. Lenders pull your credit, and too much new activity can spook them. A clean file and a lower debt-to-income ratio give you more room to negotiate.
Finally, decide what you want your life to look like after closing. Do you want to travel, save for retirement, start a business, or handle a surprise layoff without panic? A house should support those goals, not crush them. If the payment leaves you with no margin, you bought too much house. Wait, save more, or look smaller. There’s no shame in a starter home or a less trendy zip code. The goal isn’t to impress people at a cookout. The goal is to build stability, keep your credit healthy, and sleep at night. Run your own numbers. Trust your gut. And remember that the best mortgage is the one you can pay every month without turning your life into a spreadsheet you’re afraid to open.
