Mortgage rates have been sliding for months, and plenty of buyers are rushing back into the market.
But there's a number that matters more than the rate you see on a lender's website, and most shoppers have no idea where theirs stands.
It's called your debt-to-income ratio, or DTI, and it can quietly kill a home loan before a rate ever gets discussed.
Add up every monthly debt payment: car loans, student loans, minimum credit card payments, and any personal loans.
Divide that total by your gross monthly income before taxes.
If you bring in $7,000 a month and owe $700 in debt payments, your DTI is 10%.
Most conventional lenders want that number at or below 43%, and many prefer 36% or lower.
The catch is that your future mortgage payment gets folded into the calculation.
Say you earn $7,000 monthly and already owe $500 toward a car and cards.
A lender approving you at 43% DTI would allow roughly $3,010 in total monthly debt, leaving about $2,510 for principal, interest, taxes, and insurance.
In today's market, that payment supports a much smaller house than it did when rates were near 3%.
Credit card balances have climbed past $1.2 trillion nationally, and average minimum payments have grown right along with them.
Auto loan payments are near record highs too.
A buyer with great credit and a fat down payment can still get rejected because their existing debts eat too much of their income on paper.
The good news is that DTI is one of the few mortgage numbers you can actually move.
Paying down a credit card doesn't just lower the balance; it slashes the minimum payment, which drops your ratio immediately.
Lenders typically recalculate at application, so a payoff a month or two before you apply can change your approval odds fast.
Avoid opening new credit or financing furniture for that new house, since both add monthly obligations.
Self-employed buyers and anyone with variable income should pay extra attention.
Lenders often average your last two years of tax returns, and aggressive write-offs that lower your taxable income can also lower the income they'll count.
That's a real trade-off worth planning for well before you house hunt.
FHA loans are more forgiving, sometimes allowing DTIs up to 50% with compensating factors like cash reserves or a strong credit score.
But a higher ratio means a tighter monthly budget after closing, and the last thing a new homeowner needs is to be house-poor from day one.
Run your own numbers before a lender does.
A five-minute calculation could save you from a rejection, a smaller loan than you expected, or a payment that stretches you thin every month.
The bottom line: your DTI is boring, unglamorous, and probably the single most important number in your mortgage application.
Check it early, fix what you can, and shop with realistic expectations.
Final Thoughts
A slightly smaller house with breathing room beats a stretch that keeps you up at night.