Of all the numbers a lender looks at, the one that decides the most is the one borrowers understand the least. Your credit score gets all the attention. Your debt-to-income ratio, or DTI, often does the heavier lifting in whether a mortgage gets approved and on what terms. If you have ever been told your credit looks great but the loan still stalled, this number is usually why.
The good news is that DTI is not a mystery once someone shows you how it is built. It is arithmetic, and the rules about what counts are written down. This guide walks through how the debt-to-income ratio for a mortgage is calculated, which income and debts go into it, and what to do if yours is higher than you would like.
What a debt-to-income ratio actually is
Your DTI compares how much you owe each month to how much you earn each month. The CFPB describes the calculation plainly: add up your monthly debt payments and divide them by your gross monthly income, which is your income before taxes and deductions come out.
Their example is a clean one. If your mortgage payment is $1,500, your auto loan is $100, and your other monthly debts total $400, you owe $2,000 a month. On a gross monthly income of $6,000, that is a DTI of about 33 percent.
That single percentage tells a lender how much room is left in your budget after the obligations you already carry. The lower it is, the more room you have, and the more comfortable a lender is that you can absorb a new mortgage payment.
Front-end and back-end: two ratios, not one
Lenders usually look at DTI two ways.
The front-end ratio counts only your housing costs: principal, interest, property taxes, and homeowners insurance, often shortened to PITI. If your home has homeowners association dues, those go here too.
The back-end ratio counts your housing costs plus every other recurring debt payment. This is the figure most people mean when they say "DTI," and it is the one that carries the most weight in a decision.
When you read that a program allows a certain DTI, it is almost always referring to the back-end number, because that is the fuller picture of what you owe.
What income counts toward your DTI
Here is where many capable people sell themselves short, because they assume only a paycheck counts. Lenders can use most stable, documentable income. That typically includes salary and wages, self-employment income averaged over time, retirement and pension income, Social Security, and often consistent bonus, overtime, or commission income with a track record behind it.
There is one feature worth knowing about, especially for retirees and those on fixed incomes. Some non-taxable income can be "grossed up," meaning the lender counts it as a larger pre-tax figure because no income tax is taken from it. Fannie Mae's Selling Guide is the reference lenders follow for how income and debts feed the ratio. The practical effect is that a retiree living on non-taxable benefits may qualify for more than the raw deposit amount suggests, which surprises people in a good way.
The key word throughout is documentable. Income you cannot prove on paper usually cannot be counted, even when it is real. A loan officer who knows the guidelines can help you find income that qualifies and that you might not have thought to mention.
What debts count, and what does not
Your DTI includes the recurring debt payments that show up on your credit report and a few that do not. Generally counted:
- Your future housing payment, including taxes, insurance, and any HOA dues.
- Auto loans and leases.
- Student loan payments.
- Minimum payments on credit cards and other revolving accounts.
- Personal loans and installment debts.
- Court-ordered payments such as child support or alimony.
Generally not counted are the everyday living expenses that are not debts: utilities, groceries, fuel, phone bills, and most insurance premiums that are not part of your mortgage escrow. This trips people up, because their budget feels tight from those bills, yet the lender's ratio does not see them at all. The ratio is narrower than your real life, which sometimes works in your favor.
A common sticking point is the minimum-payment rule on credit cards. A card with a large balance but a small minimum payment hurts your DTI far less than the balance might suggest, because only the minimum counts. That detail matters for anyone weighing whether to pay a card down before applying.
What numbers do lenders look for
There is no single national cutoff, and that is the part the headlines miss. Different programs set different ceilings, and they move with your overall strength as a borrower.
Fannie Mae's guidelines cap manually underwritten conventional loans at 36 percent of stable monthly income, with room to go up to 45 percent when a borrower has a stronger credit profile and cash reserves. Loans run through Fannie Mae's automated underwriting can be approved at higher DTIs still, depending on the full file.
On the regulatory side, the 43 percent figure became well known because the CFPB's Qualified Mortgage rule once treated it as a hard ceiling for General QM loans. The CFPB later replaced that hard 43 percent cap with price-based thresholds, though 43 percent still gets used across the industry as a rough benchmark.
The honest takeaway is that DTI is evaluated alongside your credit, your down payment or equity, and your reserves. A higher ratio can still work when the rest of the file is solid. A lower ratio gives you options. Neither number is a verdict on you as a person. It is a measure of room in a budget, nothing more.
How to lower your DTI before you apply
If your ratio is higher than a program allows, you have real levers, and most do not require earning more overnight.
Pay down the right balances. Because revolving minimums drive the ratio, knocking out a small installment loan that is close to paid off, or reducing a card to lower its minimum, can move your DTI more than you expect.
Avoid new monthly payments. Financing a car or opening a new line of credit right before a mortgage application adds a payment to the very ratio being measured. Holding off can preserve your approval.
Document income you already have. Side income, part-time work, and certain benefits may count if you can show consistency. This is worth a conversation before you assume it does not.
Consider consolidating in the right order. For homeowners with equity, folding high-minimum debts into a single, lower payment can change the monthly math. Whether that helps your overall position depends on the full picture, the total cost, the fees, and the timeline, not on one rate in isolation. This is exactly the kind of trade-off worth modeling with someone before deciding.
Where GoodLoan fits
DTI is the number we look at with people most often, because it is so frequently the quiet reason a loan does or does not work. You are not bad with money if your ratio is high. More often, you are carrying the weight for a household, and the calculation simply has not been explained to you.
A GoodLoan loan officer can run your real numbers with you, show you the front-end and back-end ratios on your actual situation, and tell you honestly whether the timing works now or whether a few targeted moves first would put you in a stronger spot. We say no when the math says no. We would rather tell you that early than watch an application stall.
If you want to know where you stand before you commit to anything, that first conversation is a small, low-stakes step, and it is the one that tends to make everything after it clearer.
Frequently asked questions
What is a good debt-to-income ratio for a mortgage? Lower is better, and many conventional programs are most comfortable at or below 36 percent, with flexibility into the 40s when credit and reserves are strong (Fannie Mae). There is no single national cutoff, because DTI is weighed alongside the rest of your file.
Does my rent count in my debt-to-income ratio? Rent is not counted once you are buying, because your new mortgage payment replaces it in the calculation. Lenders look at the housing payment you will have going forward, not the one you are leaving behind.
Do utilities and groceries count toward DTI? No. Everyday living costs such as utilities, groceries, fuel, and phone bills are not debts and are not included. The ratio counts recurring debt obligations, not your full household budget (CFPB).
Will paying off a credit card lower my DTI? It can, because credit card minimum payments are part of the ratio. Reducing or eliminating a minimum payment lowers the debt side of the calculation, which may help more than the balance reduction alone suggests.
Can I still get a mortgage with a high DTI? Sometimes, yes. A higher ratio can be offset by a strong credit score, a larger down payment or more equity, and cash reserves. Automated underwriting may approve higher DTIs depending on the complete picture (Fannie Mae).
Is non-taxable income treated differently? Often it is. Some non-taxable income can be grossed up to a higher qualifying figure because no income tax is withheld from it, which can help retirees and others on fixed incomes qualify for more than the deposit amount implies (Fannie Mae).
