Mortgage lenders don't just look at your credit score.
They look at a single number that can quietly kill your application before a human ever reads it: your debt-to-income ratio.
And with home prices still elevated and rates hovering well above the pandemic-era lows, that number is doing more gatekeeping than ever.
DTI is all your monthly debt payments divided by your gross monthly income.
If you bring in $7,000 a month and owe $500 on a car, $200 in minimum card payments and $300 in student loans, that's $1,000 — a DTI of about 14%.
Add a $2,200 mortgage payment and you land near 46%, which is where the trouble starts.
Most conventional loans want your total DTI at or below 43%, though some programs stretch to 45% or even 50% with compensating factors like big cash reserves.
FHA loans often allow up to 43% with flexibility, and VA loans can push higher.
The point is that the ceiling is firm, and lenders verify it with pay stubs, tax returns and bank statements — not your estimate.
The trap is that buyers calculate their ratio using the mortgage payment they want, not the one they'll actually get.
Principal, interest, property taxes, homeowners insurance and HOA dues all count.
So does mortgage insurance if you're putting down less than 20%.
A $1,800 principal-and-interest figure can balloon past $2,400 once the escrow items land.
There are only two levers: earn more or owe less.
Paying off a car loan or clearing a credit card balance can drop your DTI several points overnight, sometimes more than a rate buy-down ever would.
But be careful — lenders pull your credit again before closing, and a new loan for furniture or a truck can sink a deal that was already approved.
Lenders, obviously, because lower DTI borrowers default less often.
But so do the credit bureaus and the cottage industry of "rapid rescore" services that charge to nudge your file.
Some of that is legitimate cleanup; some is a fee for something you could dispute yourself for free.
What the 43% guideline ignores is real life.
It counts gross income, not what actually hits your account after taxes and 401(k) contributions.
A household at exactly 43% can feel stretched thin in a way the spreadsheet never shows, especially with childcare, medical bills or a furnace that dies in January.
The practical move: run your own numbers before a lender does.
Add up every minimum payment on your credit reports, estimate the full housing cost including taxes and insurance, and divide by your true monthly gross.
If you're near 40%, don't panic — but don't buy at the top of your approval either.
Our take: DTI is a useful guardrail dressed up as a magic number, and treating 43% as a target rather than a ceiling is how buyers end up house-poor.
The lenders set the limit to protect themselves, not you.
Final Thoughts
Leave yourself room, because the payment is the easy part — the surprise expenses are what actually break a budget.