The share of your income that goes to debts (DTI): why they approve you for less house than you expected
Nelson Paredes · REALTOR® · One Stop Realty Center Inc
Updated September 3, 2026
50% of income
They approve you for less because of the share of your monthly income that goes to debt (DTI), which together with the full house payment cannot go past 50% of your income before taxes (your gross income).
That is the maximum that Fannie Mae (the company that buys loans from banks) allows through its automated review of your file (automated underwriting) on a regular bank loan (conventional), and everything has to fit inside it: the car, the cards, student loans and the full house payment. It is the outer limit, not a permission: when a person reviews your file by hand, a regular bank loan stops at 45%, and the government-backed loan that needs only 3.5% down (FHA) at 43% if nothing else in your file makes up for it.
The 50% is the Fannie Mae automated underwriting cap on a conventional loan; the 45% and the 43% are the limits when a person reviews your file by hand. Checked September 3, 2026. Each lender also applies its own rules when calculating income and debt.
You saved well, the cash is ready, and the number the bank came back with does not reach the neighborhood you wanted. That conversation happens most weeks.
DTI is the share of your gross monthly income (before taxes) already going to paying debts, counting the new mortgage payment. The ceiling reaches 50%: it is the maximum allowed by the automated system of Fannie Mae (the company that buys loans from banks) on a regular bank loan (conventional).
On $6,000 a month, 50% is $3,000. Inside that has to fit the car, the cards, student loans and the full house payment: the loan payment, taxes, insurance, the insurance the lender charges when you put little down (PMI / MIP), and the association fee (HOA) if it is a condo.
Item Monthly Gross income $6,000 50% ceiling $3,000 Car $500 Cards (minimums) $250 Left for the house $2,250 In that example, the car and the cards ate $750 of your ceiling. That is not $750 of house: it is tens of thousands of dollars of maximum price, because every monthly dollar compounds across thirty years of loan.
The math that surprises people. A $500 monthly car payment can be costing you up to about $73,000 of house you could otherwise reach: that is what $500 a month finances over thirty years at the current average fixed rate, 7.32% (Optimal Blue via FRED, data as of October 19, 2026). And since taxes and the home insurance also have to fit inside those $500, in practice the figure comes out lower.
So when someone is close but not there, the first thing I look at is not how much more they can save. It is which debt they can get off their back.
With your numbers, not the example. With five questions and no credit check: how many properties for sale are within your reach and what you'd pay a month.
See what I can buy- Closing one small debt completely beats paying a little toward several. DTI counts the monthly payment, not the balance: a debt paid off disappears from the calculation entirely.
- The car is usually what moves the math the most, especially if only a few payments remain. One caveat: that holds for a financed car. If it is a lease, the payment counts in full no matter how close the end of the contract is.
- Opening nothing new while you are buying. Financing furniture before closing (the day you sign and get the keys) has killed purchases that were already approved.
- Income you can prove on paper. What cannot be proven on paper does not count, even if it comes in every month.
The advantage of DTI over savings is speed: raising available cash takes months. Getting a payment off your back can change your number in weeks.
We tell you which payment to clear first.
Which ceiling applies to you, and which payment buys back the most house, comes down to how that lender counts your income and your debts, and no table shows that. Leave us your number and we run it with you.
The 50% is the maximum allowed by Fannie Mae automated underwriting on a conventional loan, and it is the outer limit, not a permission: many paths cap lower. If a person reviews your file by hand, conventional stops at 45%, and FHA at 43% if nothing else in your file makes up for it. Each lender also applies its own rules when calculating income and debt.
