One number decides how much house you can buy more than any other: your debt-to-income ratio. Income gets all the attention, but two people earning the exact same salary can qualify for wildly different loan amounts, and the reason is almost always DTI. Understand how it works and you can see your own approval coming long before you ever talk to a lender.
Debt-to-income compares your monthly debt obligations to your gross monthly income, the amount you earn before taxes. Lenders look at it two ways. The front-end ratio is just your proposed housing payment divided by your income. The back-end ratio is all your monthly debts, including the new housing payment, divided by your income. The back-end number is the one that usually drives the decision, because it captures everything you owe, not just the house.
Walk it through on $6,000 a month of gross income. If your new total housing payment is $1,800, your front-end ratio is 30%. Now add a $400 car payment, a $150 student loan payment, and $100 in credit card minimums, and your total monthly debt is $2,450. Divide by $6,000 and your back-end ratio is about 41%. That 41% is what the lender weighs against the program's limits.
This is where people get tripped up, usually in their own favor once they understand it. Lenders only count debts that appear on your credit report or that are legally required, things like:
They do not count your everyday living expenses. Groceries, gas, utilities, cell phone, insurance premiums, streaming subscriptions, none of that hits your DTI, even though it absolutely hits your budget. That gap is exactly why the lender's maximum can feel higher than what you can comfortably live with, and why what share of income should go to housing is a different question from what you qualify for.
A few specifics matter.
These details move your ratio, so they are worth knowing.
The cap depends on the loan program and on how the file gets approved. Conventional loans top out at a 50% back-end ratio with an automated approval per Fannie Mae and Freddie Mac's underwriting systems. FHA runs higher: with an automated (AUS) approval its hard ceilings are 46.99% on the housing ratio and 56.99% total DTI. Treat both as ceilings, not targets. They only apply when the automated system approves the file, most borrowers cap out below them, and nobody gets approved above them. (Program limits change over time; confirm current thresholds with a lender.)
DTI also works in combination with the rest of your file. A higher ratio can still get approved when other parts of the file are strong, like a healthy credit score, real cash reserves left after closing, or a down payment above the minimum. A lower ratio gives you room to absorb a weakness somewhere else.
Because DTI is a fraction, you improve it by shrinking the top or growing the bottom. Paying off or paying down a debt with a high monthly payment is the fastest lever, and note that it is the monthly payment that matters, not the total balance. Knocking out a $400 car payment frees up far more borrowing power than paying down a credit card with a $25 minimum. On the income side, documented and stable additional income, like a consistent bonus history or a second job with a track record, can raise the denominator. What you want to avoid is taking on any new monthly payment, a new car especially, in the months before you buy.
Nothing tanks a pre-approval faster.
Your debt-to-income ratio is the lever the lender pulls to set your maximum loan amount, and it rewards you for carrying fewer fixed monthly payments, not for earning a specific salary. Jeb and Josh come back to the same advice on the show again and again: treat the program maximum as a ceiling rather than a goal. Know your number before you shop, know what to do if a lender says no, and remember that the only debts working against you are the ones a lender can see. The fastest way to learn that number for real is a free Roadmap conversation, which gets you your actual qualification range and payment.
Stop guessing what you can really afford
Tell Josh and his team your situation, and you'll get the exact price range you qualify for, the loan that gets you the most home for your money, and a step-by-step plan to close. They handle your loan directly, never a referral, and go far beyond a basic pre-approval, so you stop second-guessing, tour with confidence, and write offers sellers take seriously.
Build my Roadmap →Add up your monthly debt payments including the proposed housing payment, then divide by your gross monthly income (before taxes). That figure is your back-end DTI, the number lenders weigh most. The front-end ratio is just the housing payment divided by income.
Obligations that show on your credit report or are legally required: car loans, student loans, credit card minimum payments, personal loans, and child support or alimony. Everyday expenses like groceries, utilities, insurance, and subscriptions do not count, even though they affect your real budget.
It depends on the loan program and how the file is approved. With an automated approval, conventional loans top out at a 50% back-end ratio and FHA's hard ceilings are 46.99% housing and 56.99% total DTI — maximums no borrower can exceed, and most files cap out lower. These limits change over time, so confirm current numbers with a lender.
Yes, and it is often the most powerful lever. Because DTI is driven by monthly payments, eliminating a debt with a high monthly payment, like a car loan, frees up more borrowing power than paying down a balance with a small minimum, like a credit card.
Only the required minimum payment counts toward your DTI, not the full balance. That said, a high balance relative to your limit can lower your credit score, which affects your rate and approval separately. Paying balances down before applying helps on both fronts.