If you have been house hunting this spring, you have probably noticed that the math on the mortgage worksheet does not look like it did a few years ago.
The reason is not just the headline interest rate, which has been hovering in the mid-6% range for a 30-year fixed loan.
It is the debt-to-income ratio, or DTI, the quiet gatekeeper that decides whether you qualify at all.
Lenders add up every minimum monthly payment you owe, from car loans to student debt to credit card minimums, then divide that total by your gross monthly income.
Most conventional loans want that number at or below 36%, though some programs stretch to 43% or even 50% with compensating factors.
Cross the line and you are not rejected outright; you are simply quoted a worse rate or asked to bring more cash.
That threshold matters more now because everything else got more expensive at the same time.
The Federal Reserve's rate hikes pushed borrowing costs up across the board, so the same DTI that qualified you for a comfortable payment in 2021 now prices you out of the same house.
Renters feel it too, because landlords increasingly run the same calculation before approving a lease.
When the Bureau of Labor Statistics reported that food prices rose roughly 25% over four years, that is money that never reaches your savings account.
A paycheck that used to cover a $400 car payment and leave room for a mortgage now gets stretched thinner, and lenders see the strain in your bank statements.
The average APR on a new card offer has been running above 20%, and if you carry a balance, the minimum payment climbs with it.
A $10,000 balance at 22% can add $200 or more to your monthly obligations, which is enough to push a borderline DTI over the edge and cost you tens of thousands in extra interest over the life of a 30-year loan.
Pay down revolving debt first, because credit card minimums hit DTI harder than almost anything else per dollar owed.
Avoid financing a new car in the six months before you apply.
And ask your loan officer to run your numbers before you fall in love with a listing, not after.
One overlooked move: a larger down payment lowers the loan amount, but it does not change your DTI directly.
What changes DTI is reducing the monthly payment obligations on the report, which is why paying off a small installment loan can sometimes do more for your approval odds than saving another $5,000.
In a market where rates are sticky and prices are not falling, your DTI is the lever you can actually pull.
Final Thoughts
Treat it like a credit score you can improve on purpose, and you will have more options when the right house shows up.