What lenders measure, what the numbers say for a typical family in 3,063 counties, and why the figure a lender approves is a ceiling rather than a target.
The first is housing: principal and interest, property tax, homeowners insurance, mortgage insurance and any HOA dues, all together, should stay under about 28% of gross monthly income. The second is everything: housing plus car loans, student loans and credit card minimums, under about 36%. Both are measured against income before tax, which is the number lenders can verify, not the one you live on.
On the median county income of $80,388, the first limit is $1,876 a month and the second is $2,412. The gap between them, 8% of income or $536 a month, is room for other debts that costs nothing: payments under it do not lower the ceiling at all, and every dollar over it does. With $40,000 down at 7.03%:
| Other debt payments | Most house | Limit that binds |
|---|---|---|
| $0 a month | $246,623 | Housing (28%) |
| $300 a month | $246,623 | Housing (28%) |
| $600 a month | $238,823 | All debt (36%) |
| $900 a month | $202,304 | All debt (36%) |
A $300 car payment is invisible to the lender here. A $900 one takes $44,319 off the house. Which one you carry into the application matters more than almost anything you can do in the month before it.
Put Zillow's typical home value for each county beside the median family income the Economic Policy Institute reports for the same county, for the 3,063 counties with their own home value. The median county's typical home is worth $234,145 and its median family earns $80,388. The median ratio of the two is 2.99: a typical home costs about three years of a typical family's gross income.
With 10% down at 7.03%, that home costs $1,894 a month: $1,406 of principal and interest, $215 of property tax, $142 of insurance and $132 of mortgage insurance. Passing the 28% test on it takes $81,182 a year, just past the median family's income. Across counties, the median family can afford its own county's typical home in 44.9% of them.
The spread is enormous. A typical home costs more than 17 years of median family income in Nantucket County, Massachusetts (20.9), Pitkin County, Colorado (20.7) and Teton County, Wyoming (17.1), and less than one year in a cluster of rural Texas and Oklahoma counties. One caution about all of this: every county counts once, so a county of a few thousand people weighs the same as Los Angeles. These figures describe places, not the average American household.
Principal and interest are most of the payment, so the rate decides most of the price. For a family on $80,388 with $40,000 down and no other debts, the 0.73-point rise in the average 30-year rate over the year to September 2026 took $12,921 off the most house the 28% limit allows, 5.0% of it.
The down payment works the same way from the other side. On the median county's $234,145 home, going from 10% down to 20% takes the monthly cost from $1,894 to $1,606: a smaller loan, and no mortgage insurance at all.
Because the ratios use income before tax, a payment at exactly 28% is a larger share of what actually reaches your account. For a married couple on $80,388 in a state with no income tax and no deductions, it is 32.6% of take-home pay. Add a state income tax, a 5% retirement contribution and $300 a month of health premiums, as in Colorado, and it is 37.9%.
And the ratios leave out what owning costs beyond the loan. A common rule of thumb budgets about 1% of a home's value a year for maintenance, around $195 a month on the median home, and the cash for closing costs has to come from somewhere other than the down payment. Some loan programs approve back-end ratios well above 36%. That is a statement about the lender's risk, not about your budget.
Conventional loans are available with as little as 3% down and FHA loans with 3.5%. Under 20% you pay mortgage insurance, which on the median county home at 10% down is $132 a month, so 20% is the point where that cost disappears, not the price of entry.
A mortgage quote is principal and interest. The bill also carries property tax, insurance and often mortgage insurance, which add $488 a month to the median home's $1,406, before any repairs a landlord used to cover.
Pre-approval tells you what a lender will lend against gross income. At 28% of gross, the payment can already be 32.6% to 37.9% of take-home pay, before maintenance.
Home values are Zillow's typical home value for each county as of July 2026; incomes are the median family income in the Economic Policy Institute's 2026 family budget data. Affordability uses 10% down, a 30-year loan at 7.03%, 1.1% property tax, $1,700 a year of insurance, mortgage insurance at 0.75% of the loan and the 28% housing limit, computed with the same code as the home affordability calculator.
Nothing is saved or sent anywhere; this just checks your answers in the page itself.
Counties are unweighted, so these figures describe the spread of places rather than of people. Property tax and insurance vary a great deal by state and county; the calculator lets you use your own.