Mortgage rates have been bouncing around the mid-to-high 6% range for months, and that single fact has quietly rewritten the rules of home buying.
The number lenders care about most right now isn't your credit score or your down payment.
It's your debt-to-income ratio, or DTI, and it has turned into the single biggest gatekeeper between a buyer and a house.
When rates were 3%, a buyer could stretch further because the monthly payment stayed manageable.
At today's rates, every dollar of existing debt eats into how much house you can afford.
Lenders typically want your total monthly debt payments — mortgage, car loans, student loans, minimum credit card payments — to stay under 43% of your gross monthly income.
Some loan programs allow up to 50%, but crossing that line often means a denial or a much smaller approval.
A household earning $7,000 a month with a $450 car payment and $200 in credit card minimums has roughly $2,360 left for housing if it targets a 43% DTI.
In many metros, that budget no longer buys a starter home.
The same family would have qualified for a significantly larger loan two years ago.
What's tripping people up most is the debt side, not the income side.
Minimum credit card payments count against you even if you pay the balance in full every month.
A single $8,000 card balance with a 2% minimum adds $160 to your DTI calculation.
Pay that card down before applying and you can shift your approval by tens of thousands of dollars in purchase price.
Lenders generally use 1% of the outstanding balance as the monthly payment for DTI purposes, or the actual payment if it's higher.
Borrowers on income-driven repayment plans sometimes get hit with a calculation that's far above what they actually pay.
Ask your lender which figure it uses before you fall in love with a listing.
Pay down revolving debt first, since it moves your DTI fastest.
Avoid financing a car or furniture in the six months before you apply.
And get a pre-approval early, because it tells you the real number instead of the one you guessed at.
One more thing worth knowing: Fannie Mae and Freddie Mac have been phasing in automated income verification, which means lenders see your deposits and debts faster than ever.
Fudging numbers on an application is a faster path to a denial than it used to be.
If you're shopping right now, treat your DTI as a live score you can improve.
Every card you pay off and every loan you close before applying is real leverage — arguably more than another $5,000 in down payment. **Our take:** DTI has quietly become the housing market's real affordability test, and most buyers don't check it until a lender does it for them.
Final Thoughts
Run the math yourself before you tour a single house — it's free, fast, and it will save you from a rejection you could have avoided.