Free affordability calculator based on the 28/36 rule lenders actually use. No signup. No email. Just an answer.
Based on the 28/36 rule lenders actually use.
Lenders want your housing costs under 28% of gross monthly income and your total monthly debt under 36%. Those two caps — front-end and back-end — decide what you can borrow. This calculator solves the equation backwards: given your income and debts, what is the biggest home price that keeps you inside the caps?
A 2024 survey by Fannie Mae found that 60% of first-time buyers exceeded the 36% back-end cap in their first year of ownership, and 41%reported "house poor" stress within 24 months. The conservative cap exists for a reason.
Four numbers, one answer.
Gross household income plus minimum monthly payments on credit cards, student loans, and car loans.
Conservative (28%), moderate (33%), or aggressive (36%). Most first-time buyers should stay at moderate or below.
Today's average 30-year fixed is ~6.75%. Your bank pre-approval letter has your exact rate.
We solve for the home price where total monthly payment exactly equals your DTI cap — that is your ceiling.
Other free tools for the home buying math.
Lenders cap your housing payment at 28% of gross income and your total debt at 36%. Here is what that actually means for your house hunt.
A realistic walkthrough for a $100k earner. Including what changes at 20% down, 10% down, and no down payment at all.
Debt-to-income ratio is the single biggest factor in your mortgage approval — bigger than credit score for most borrowers.
Being approved for a mortgage and being able to afford one are not the same thing. Five signals you are about to overextend.
On a $100,000 annual salary with no other debts, a 20% down payment, and a 6.75% mortgage rate, most lenders would approve you for a home in the $300,000–$360,000 range. The exact number depends on your monthly debts, property taxes, and insurance. Use our calculator to get a precise answer.
The 28/36 rule is the affordability guideline most lenders use. Your housing payment (principal, interest, taxes, insurance) should not exceed 28% of gross monthly income. Your total debt payments (housing plus all other debts) should not exceed 36% of gross monthly income. Many lenders allow up to 43% or even 50% for qualified borrowers, but 36% is the conservative cap.
Putting 20% down avoids private mortgage insurance (PMI), which typically costs 0.5%–2% of the loan per year. That said, FHA loans allow 3.5% down, conventional loans as low as 3%, and VA/USDA loans 0% down. A smaller down payment gets you into a home faster but raises your monthly payment and total interest paid.
Monthly debt for DTI includes minimum credit card payments, student loans, auto loans, personal loans, alimony, child support, and any other recurring obligations reported on your credit report. It does NOT include utilities, groceries, gas, or insurance premiums (other than the new home insurance).
Property taxes vary from under 0.5% (Hawaii, Alabama) to over 2% (New Jersey, Illinois, New Hampshire). On a $400,000 home, a 2% tax rate adds $667/month vs $167/month at 0.5% — a $500 difference that shrinks the house price you can afford at the same DTI cap. Always plug in your local rate.
Some lenders approve DTIs up to 50% for strong applicants (high credit score, cash reserves, stable income). But approved does not mean affordable. Borrowers at 45%+ DTI report significantly higher rates of financial stress, missed payments, and regret within 2 years of purchase. The conservative 36% cap exists for a reason.
A mortgage calculator tells you the payment for a given home price. This affordability calculator works backwards — it tells you the maximum home price that keeps your DTI within lender limits, given your income and debts. Use this before house hunting so you do not waste time on listings outside your approval range.
Yes. HOA is a direct monthly input. For PMI, add an estimated monthly PMI amount (typically $30–$70 per $100,000 borrowed if you put less than 20% down) into the home insurance field. A full breakdown of PMI rules is in our Glossary.