Your credit score is 720. Your DTI is 48%. Guess which one matters more when you apply for a mortgage.
I’ll save you the suspense – it’s the DTI. Every time.
I learned this the hard way. Back when I was still at the bank, I had a client – great guy, made $90k a year, credit score around 740. He wanted to buy a house. We pulled his file. His DTI was 49%. Denied. He was furious. “I’ve never missed a payment,” he said. “I have excellent credit. Why won’t you lend to me?”
Because DTI tells lenders how much of your income is already spoken for. Credit score tells them how reliable you’ve been in the past. Both matter. But DTI is the gatekeeper. You can have an 800 credit score, but if your DTI is over 43%, a lot of lenders won’t touch you. Meanwhile, someone with a 660 score and a 30% DTI might get approved the same day.
So what is DTI, exactly?
Debt-to-income ratio is simple: all your monthly debt payments divided by your gross monthly income. That’s it. A fraction. A percentage.
Let me give you a real example. Someone I worked with – call her Jenna – made $5,000 a month before taxes. Her debts were: mortgage $1,500, car loan $400, student loan $300, minimum on two credit cards $250. Total monthly debt payments: $2,450. Divide $2,450 by $5,000. That’s 0.49, or 49%.
Lenders break DTI into two parts: front-end (housing only) and back-end (all debt). For a conventional mortgage, they usually want front-end under 28% and back-end under 43%. Jenna’s front-end was 30% ($1,500/$5,000) – a little high. Her back-end was 49% – way over. She didn’t qualify for the loan she wanted.
She asked me, “How do I fix this?” Two ways: increase income or decrease debt.
She chose decrease debt. We attacked her credit cards first – smallest balances to get quick wins – then the car loan. Over about 14 months, she lowered her monthly debt payments by $650. New back-end DTI: 36%. She reapplied and got approved.
That’s the power of knowing your number.
You can use that calculator in about 90 seconds. Pull up your pay stub and your latest statements. Plug in the numbers. See where you stand.
Now, here’s where people get confused. They think DTI only matters when you’re applying for a mortgage. Not true. Landlords use it. Car dealerships use it. Some employers even check it for certain jobs. Your DTI follows you around.
I remember a guy – a firefighter named Dave – who came to me because his apartment application got rejected. He made $65k a year, had a credit score of 710. His DTI was 47% because of a huge truck payment and some old student loans. The landlord didn’t care about his credit score. They saw 47% and said “too risky.” Dave was stunned. He’d never even heard of DTI before.
We worked on paying down the truck loan early. It took him about eight months. His DTI dropped to 38%. He got the next apartment he applied for. He texted me a photo of his keys.
So what’s a good DTI? Less than 36% is generally considered healthy. Under 28% is excellent for housing costs alone. Between 36% and 43% is borderline – you might still get approved, but you’ll pay higher rates. Above 43% is trouble. Above 50% is crisis territory.
But those numbers aren’t absolute. If you have a huge income, lenders might go higher. If you have a tiny income, they might cut you off lower. A friend of mine who’s a doctor makes $400k a year. His DTI could be 50% and he’d still be fine because his disposable income after debts is huge. A teacher making $45k with a 45% DTI is in a much tighter spot.
That’s why I always tell people to look at the raw numbers, not just the percentage.
Another thing: DTI doesn’t care about your expenses other than debt. It ignores groceries, utilities, gas, childcare, insurance. Those costs can be huge. So DTI can look fine on paper while your actual budget is drowning. I’ve seen people with 32% DTI who can’t afford to eat out because their other bills are crushing them. The reverse is also true – someone with 45% DTI but no kids, no car, no cable might be perfectly comfortable.
So treat DTI as one tool, not the whole story.
You can use that to see how quickly you could lower your DTI by paying off specific debts. Usually, targeting the smallest balance gives you the fastest DTI drop because you eliminate a whole payment sooner. That’s the snowball method working on your DTI, not just your motivation.
Now, a controversial take: some financial gurus say you shouldn’t worry about DTI at all unless you’re about to apply for a loan. I disagree. DTI is like your blood pressure. You don’t wait until you’re having a heart attack to check it. You monitor it regularly, because it tells you whether you’re heading toward trouble.
I had a client – let’s call him Paul – who didn’t check his DTI for years. He was making good money, around $110k, but he kept buying things on credit. New boat, new ATVs, a truck to pull them. His DTI crept up to 48% without him noticing. Then his hours got cut at work. Suddenly his income dropped to $80k. His DTI shot up to 66%. He couldn’t make his payments. He almost lost his house. All because he wasn’t watching the ratio.
I’m not saying you need to check your DTI every week. But once a quarter? Yeah. That’s smart. Just like you check your credit score once in a while.
So how do you lower DTI if it’s too high? Three levers.
First, increase income. Easier said than done, I know. But even a side gig that brings in $500 a month can lower your DTI by a few points. If you’re borderline for a mortgage, that might be enough to push you over the approval line.
Second, pay off debts. This is obvious. But pay attention to which debts. Paying off a small debt with a low monthly payment – like a $100 minimum – will lower your DTI just as much as paying off a huge debt with a $500 minimum. So if you’re in a hurry to improve your DTI for a loan, target the debts with the smallest monthly payments first. That might mean paying off a $1,000 store card before a $10,000 credit card, even if the interest rate is lower. Because the store card’s minimum payment might be $100, and the big card’s minimum might be $200. Eliminate the $100 payment first. Your DTI drops faster.
Third, don’t take on new debt. This sounds obvious, but you’d be surprised. I’ve seen people get a new car loan six months before applying for a mortgage. Their DTI jumps by 10 points overnight. Then they wonder why they got denied. The rule: if you’re planning to apply for a major loan in the next year, freeze your credit. No new accounts. No new inquiries. Keep your DTI as low as possible.
That tool is useful for understanding how much of your monthly payment is actually going toward reducing your debt. Because on a long loan, like a 30-year mortgage, your early payments are mostly interest. So your DTI doesn’t improve much for years. That’s why I tell people to focus on short-term debts first if they want to move the DTI needle quickly.
Here’s the bottom line, and it’s not a summary. DTI is one of the most underrated numbers in personal finance. People obsess over their credit score, ignore their DTI, and then get rejected for loans and don’t understand why. Check yours today. It takes five minutes. If it’s over 40%, make a plan. If it’s over 50%, make a serious plan. If it’s under 30%, congratulations – you’re in great shape.
P.S. The guy with the boat and the ATVs – Paul – ended up selling the boat. He paid off the credit cards. His DTI dropped to 32%. He kept his house. He told me “I should have checked that number three years ago.” Yeah. Probably.
James Whitfield
