Home Affordability Calculator

Home Affordability tells you the price you can qualify for before you start shopping, working backward from your income, existing debt, and a lender's typical debt-to-income ceiling. It sits upstream of the Home Loan and Debt-to-Income calculators, both of which assume you already have a price or payment in mind.

This calculator solves for the price itself, then shows whether your existing debt or the housing payment alone is what is actually limiting you.

How does this calculator work?

This is a solve-for-anything tool: switch between three modes depending on the question you're asking. "Home Price From Income" works backward from your income, debt, and a DTI ceiling. "Home Price From a Payment" skips that and lets you enter a monthly payment you already know you're comfortable with. "Income Needed For a Price" runs the math the other direction, telling you the income required to qualify for a specific home price. If you already know your exact debt load, you can check your debt-to-income ratio directly first.

Whichever mode you use, the same underlying math applies: property tax scales with the home price itself, so price and tax are solved together rather than guessed and checked. A full amortization schedule, yearly or monthly, is available for whatever loan amount results.

The income-based mode also flags which constraint is actually binding: often your other debt payments limit you more than the house itself would, and paying down debt raises your max price more than shopping for a slightly better rate does.

How lenders determine what you can afford

Lenders qualify buyers primarily on debt-to-income ratio: your monthly debt payments as a share of gross monthly income. Front-end DTI looks at the housing payment alone; back-end DTI adds every other recurring debt, auto loans, student loans, credit cards, and anything else on a credit report, and is the number most lenders weigh most heavily.

Conventional loans commonly cap back-end DTI around 36-43%, though some programs allow higher ratios for well-qualified borrowers. Because back-end DTI counts existing debt, two buyers earning the same income can qualify for very different home prices depending on what else they owe each month.

What is included in your monthly payment

A mortgage payment is rarely just principal and interest. PITI, principal, interest, taxes, and insurance, is the fuller picture lenders actually qualify against, and this calculator budgets for all four rather than just the loan payment alone.

Property tax and homeowners insurance vary a lot by location, so the defaults here are rough national estimates meant to be edited. HOA dues, if the property has them, stack on top of PITI and reduce how much loan payment your budget can support. Once you have a target price in mind, the Home Loan Calculator shows the exact payment and full amortization schedule for that specific price.

How down payment size changes affordability

A bigger down payment raises your max home price dollar for dollar in the simplest sense, since it covers part of the price without adding to the loan. But it also shrinks the loan amount needed for any given price, which lowers the monthly principal and interest payment, freeing up room in your DTI ceiling for an even higher price.

Toggle the down payment field between a dollar amount and a percent of price to see both framings: a fixed dollar amount is easier to plan around if you have a set amount saved, while a percentage keeps the down payment proportional as you test different price points.

Getting pre-approved vs. this estimate

This calculator is a planning tool, not a lending decision. Actual pre-approval depends on your lender verifying income, assets, credit history, and the specific loan program's guidelines, all of which can move the real number up or down from this estimate.

Use this to narrow your search to a realistic range before you talk to a lender, then get pre-approved for the real number. If rates improve after you buy, look into refinancing later; and if you are buying land separately from a home, a land loan works differently since land purchases are financed on their own terms.

Worked example

$90,000 annual income, $450 in existing monthly debt, a $40,000 down payment, a 6.75% rate over 30 years, and a 36% DTI ceiling.

Gross monthly income

$7,500

Max PITI at 36% DTI

$2,250

Maximum home price

$323,232

Loan amount

$283,232

Estimated monthly payment

$2,250

How the numbers work

36% of $7,500 income is $2,700; subtracting the $450 in existing debt leaves $2,250 a month for the housing payment itself.

Working backward from that $2,250 ceiling, after setting aside property tax and insurance, the calculator solves for the loan amount the remaining payment supports, then adds the $40,000 down payment to get the maximum home price.

The $450 in existing debt is not dramatic on its own, but it directly reduces the housing budget dollar for dollar. Paying it off would free up the full $450 toward a bigger home price, more than a small rate improvement would.