Mortgage rates have been bouncing around in the low-to-mid 6% range for months, and plenty of buyers have adjusted their budgets accordingly.
But there's a second number that lenders care about just as much as the rate, and it quietly knocks more applicants out of the running than almost anything else.
That number is your debt-to-income ratio, or DTI.
It compares everything you owe each month — car payments, student loans, minimum credit card payments, rent — against what you bring in before taxes.
Add up your monthly debt payments and divide by your gross monthly income.
If you earn $6,000 a month and owe $1,800 across all debts, your DTI is 30%.
Most conventional lenders prefer a DTI at or below 36%, though some loan programs allow up to 43% or even higher with compensating factors like strong savings.
Cross that line without backups, and you can expect a denial letter.
In a strange twist, the past few years of inflation actually made DTI harder to manage for many households.
Wages rose, but so did car loan payments, insurance premiums, and credit card balances.
A raise that looks great on paper can be erased by a bigger monthly payment on a replacement vehicle.
Here's the part that surprises people: lenders count the minimum payment on your credit cards, not your full balance.
So a $6,000 card balance might only add $150 to your monthly debt load.
That's why paying down cards — or consolidating them — can move your DTI faster than you'd expect.
If you're house hunting, run your own numbers before a lender does.
Pull your latest pay stubs, add up every recurring debt payment, and do the division.
Knowing where you stand lets you fix problems early, whether that means paying off a small loan or waiting a few months.
One overlooked lever is paying off an installment loan entirely.
Clearing a $350 monthly car payment can drop your DTI by nearly 6 percentage points on a $6,000 income — often the difference between a yes and a no.
Also be careful about new credit during the mortgage process.
Financing furniture or a new truck between preapproval and closing can sink your ratio overnight, and lenders typically recheck your credit right before funding.
Self-employed buyers and anyone with variable income should expect extra scrutiny, since lenders average your earnings over two years.
A strong tax return helps, even if it means a bigger tax bill.
The bottom line is that DTI is one of the few mortgage rules you can actually control.
Rates are set by the market, but your ratio is set by your choices — and a few months of focused payoff can change the answer.
Our take: if you're even thinking about buying in the next year, calculate your DTI this week.
Final Thoughts
It's a free, ten-minute exercise that tells you more about your odds than any online rate quote will, and it gives you time to fix what needs fixing before it costs you a house.