"How much house can I afford?" is really two questions: how much a lender will give you, and how much you can comfortably repay. The gap between those can be huge — and chasing the first number is how people end up "house poor." The 28/36 rule is the time-tested guideline that keeps the two in line.
The 28/36 rule in one sentence
Keep your housing payment under 28% of your gross monthly income, and your total debt payments under 36%. Gross means before tax. "Housing payment" is the full thing — principal, interest, property taxes and insurance (PITI), plus HOA if any — not just the loan.
What counts as debt
The 36% "back-end" number includes the new housing payment plus car loans, student loans, minimum credit-card payments and any other monthly obligations. Things like groceries, utilities and subscriptions don't count here — lenders look at debt, not lifestyle. Paying off a car before applying can meaningfully raise the price you qualify for.
A worked example
Say you earn $90,000 a year — $7,500 a month gross. The 28% cap puts your housing payment at about $2,100. If you also have $500/month in other debts, the 36% cap allows $2,700 total minus $500 = $2,200 — so the 28% rule is the binding limit at $2,100. With a 20% down payment and a 6.5% rate, that payment supports a home somewhere around the high $300,000s once taxes and insurance are carved out. The home affordability calculator does this exact math instantly.
Down payment changes everything
A bigger down payment shrinks the loan, lowers the monthly payment and — past 20% — drops private mortgage insurance (PMI). It's often the single biggest lever you control. If you're still saving toward it, the savings goal calculator tells you how much to set aside each month to hit your target by a deadline.
Don't forget the costs around the loan
Closing costs (2–5% of the price), moving, and an emergency fund for repairs all sit outside the mortgage. A payment you can technically afford on paper can still leave you with no cushion. Build those into your plan before you stretch to the top of your range.
Run your own numbers
Start with the home affordability calculator to find your ceiling, then use the mortgage calculator to see the full monthly payment (with taxes, insurance and PMI) for a specific price. Together they turn "how much house can I afford?" into a concrete, confident number.