"How much can I afford" has two very different answers: the number a lender will approve you for, and the number you can comfortably live with. They're rarely the same. A lender looks at ratios on paper; it doesn't know about your car payment stress, your savings goals, or how much cushion helps you sleep at night. This tool aims at the second number — what actually fits your life — not just the maximum a bank will sign off on.
The 28/36 rule, and why it's a starting point, not a law
Most affordability math is built on two ratios lenders use. The front-end ratio says your housing payment should stay around 28% of your gross monthly income. The back-end ratio says all your debt payments together — housing plus car loans, student loans, credit cards — should stay near 36%. These are useful guardrails, but they're maximums, not targets. Plenty of people are approved at these limits and end up house-poor, with a home they technically qualified for but can't comfortably afford once real life shows up. Treat the ratios as a ceiling to stay under, not a goal to hit.
Gross income lies a little
Affordability rules use gross income — what you earn before taxes and deductions. But you pay your mortgage with take-home pay, which can be 20-30% lower after federal tax, state tax, Social Security, Medicare, and things like health insurance and retirement contributions. A payment that looks fine against your gross salary can feel much tighter against what actually lands in your account. This is why a realistic affordability number leaves room — and why it's worth checking your actual take-home pay before deciding what you can spend.
The down payment changes everything
Your down payment does more than lower the loan amount. Below 20% down, you'll pay PMI, which adds to the monthly cost. A larger down payment shrinks the loan, removes PMI, and lowers your monthly payment on two fronts at once. But there's a real tradeoff: draining your entire savings into a down payment to avoid PMI can leave you with no emergency fund, which is its own kind of risk. The healthiest position is usually enough down to keep the payment manageable while still keeping months of expenses in reserve. Adjust the down payment above and watch how the affordable price and the monthly payment move together.
Where you buy quietly reshapes the number
Two buyers with identical incomes can afford very different homes depending on location. Property tax rates swing from under 0.6% of home value per year in some states to over 2% in others, and homeowners insurance has risen sharply in coastal and disaster-prone areas. Those recurring costs eat into the same monthly budget that would otherwise go toward the mortgage itself — so in a high-tax, high-insurance state, the home price you can afford is meaningfully lower for the same paycheck. Selecting your state above folds these real local costs into the estimate.
The costs that don't show up in the ratio
Lender ratios cover the mortgage payment, but owning a home costs more than the payment. Maintenance runs roughly 1% of the home's value per year as a rule of thumb — a $400,000 home means budgeting around $4,000 annually for repairs and upkeep that a renter never sees. Add closing costs upfront, potential HOA dues, higher utility bills than an apartment, and the furniture and fixes a new place always seems to need. A home you can afford on paper but that leaves nothing for these realities isn't truly affordable. Building a buffer for them is what separates a comfortable purchase from a stressful one.
How to use this number
The figure above is a realistic ceiling, not a shopping target. A few honest ways to use it: shop below your maximum, not at it, so you have room for the costs the ratio ignores. If the affordable number is lower than you hoped, the levers are clear — raise your down payment, pay down existing debt to free up your back-end ratio, or look at areas with lower property taxes. And before you commit, pressure-test the monthly payment against your actual take-home pay and your other goals. The best home isn't the most expensive one you can get approved for; it's the one that still lets you live the rest of your life.