How Much House Can I Afford? (28/36 Rule)
Enter your income, monthly debts, down payment, and today's rate. You'll get a comfortable price range, your maximum monthly payment under the 28/36 rule, and the loan amount behind it.
Household income before taxes
Car loans, student loans, credit card minimums
Cash you can put toward the purchase
Today's quoted rate for your credit profile
30 years is the standard mortgage
Comfortable price range
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Enter your income to see it
Max monthly payment (P&I)
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the lower of the 28% and 36% rules
Loan amount
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The 28/36 rule from the lender's chair
Lenders don't ask what house you want; they ask what payment your income can carry. The front-end test caps housing at 28% of gross monthly income. The back-end test caps housing plus every other debt payment at 36%, which is why a $450 car payment quietly deletes about $70,000 of house from your budget. The calculator takes whichever cap is lower, converts that payment into a loan at today's rate, and adds your down payment. The same logic drives your debt-to-income ratio, the number underwriters actually quote, and our DTI guide walks through how they read it.
Pre-approval is a ceiling, not a target
Banks will often approve payments that push total debt to 43-50% of gross income, so a pre-approval letter can run 30-40% above the comfortable number this calculator shows. The bank is pricing its risk of not being repaid; it is not pricing your vacations, retirement contributions, or the year your roof fails. Buyers who borrow the full approval discover the difference one budget cycle at a time. A useful sanity check: if the payment would break the logic you'd apply to rent, approval doesn't make it affordable.
The payment is only the opening bid
Principal and interest are the visible cost. Property taxes, insurance, and maintenance (plan on roughly 1% of the home's value per year) arrive on top, and none of them build equity. That's why the comfortable range shown here starts below the mathematical maximum. Once you have a target price, the mortgage calculator turns it into an exact payment and amortization schedule, and the down payment guide covers building the cash. Keeping the whole picture (savings, debts, and the goal itself) in one view is what Stoia is for.
Frequently asked questions
What is the 28/36 rule?
The classic lending guideline: housing costs should stay under 28% of your gross monthly income, and housing plus all other debt payments should stay under 36%. Your affordable mortgage payment is whichever limit binds first. It has screened U.S. mortgage applications for decades because homeowners inside those lines rarely get into payment trouble.
Is the 28% based on gross or take-home income?
Gross, before taxes. That makes the rule more permissive than it sounds: 28% of gross can be 35-40% of what actually lands in your account. If you want a conservative budget, run the numbers and then shop near the bottom of the range the calculator shows.
Why is my pre-approval higher than this number?
Lenders routinely approve debt-to-income ratios up to 43-50% on qualified mortgages, well past the 36% comfort line. A pre-approval is the most the bank will lend, not a recommendation. The gap between approval and comfort is where house-poor budgets come from.
How much should I put down?
20% avoids private mortgage insurance and shrinks the loan, but the median first-time buyer puts down far less (single digits is common). A smaller down payment means a bigger loan, PMI, and a tighter monthly budget, so the real question is what payment the 28/36 math supports after the down payment you have.
What costs does the mortgage payment not include?
Property taxes, homeowners insurance, PMI if you put down under 20%, HOA dues, and maintenance, which averages roughly 1% of the home's value per year. Together these commonly add $500-1,000 a month to the principal-and-interest payment, which is why shopping at your maximum rarely feels like it on move-in day.
Does this calculator save my numbers?
No. Everything runs in your browser and disappears when you leave. Nothing is uploaded or stored.
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