The number that quietly decides whether you get a mortgage isn't your credit score.
It's your debt-to-income ratio, and lenders have been getting pickier about it all year.
Debt-to-income ratio, or DTI, is everything you owe each month divided by your gross monthly income.
If you bring in $6,000 a month and your car loan, student loans, minimum card payments and a new housing bill add up to $2,700, your DTI lands at 45%.
That's the line where a lot of conventional loans start to wobble.
With mortgage rates still hovering well above the lows of 2021, a higher rate pushes your monthly payment up, which pushes your DTI up, even if you're buying the exact same house at the exact same price.
Buyers who qualified easily two years ago are getting sidelined today for reasons that have nothing to do with their down payment.
The classic guideline is the 28/36 rule: housing costs under 28% of gross income, total debt under 36%.
But many conventional lenders will stretch to 43%, and some government-backed loans go higher with compensating factors like bigger reserves or stellar credit.
The catch is that "will stretch" and "will approve" are different things.
A 43% DTI with a thin savings account and a 640 score is a very different file than the same ratio with 12 months of reserves and a 780.
Lenders pull your minimum payments on credit cards, not your current balance.
Auto leases, personal loans, child support and student loans all count.
A $40,000 student loan on an income-driven plan might count as a smaller payment, but some lenders still use 1% of the balance as a stand-in.
The fastest way to fix a shaky DTI is boring but effective: pay down revolving debt before you apply.
Knocking out a $250 monthly card payment on a $6,000 income cuts your DTI by more than four points.
Adding a co-borrower with clean finances can also move the needle.
One more thing worth knowing: stretching to the max DTI leaves you no cushion.
A single car repair or a medical bill turns into a credit card balance, and suddenly the budget that looked fine on paper is tight. **The bottom line:** your DTI is a snapshot, not a life sentence, and it's one of the few pieces of the mortgage puzzle you can actually move before you apply.
Pull your numbers, run the math, and pay down the plastic first.
Final Thoughts
It beats house-hunting for months only to get a pre-approval rejection.