Your debt-to-income ratio (DTI) is your total monthly debt payments divided by your gross monthly income, expressed as a percentage. If you pay $2,000 a month toward debts and earn $6,000 before taxes, your DTI is 33%. Lenders use this single number to judge whether you can comfortably take on a new loan, so knowing how to calculate it yourself puts you a step ahead before you apply for a mortgage, auto loan, or credit card.
The Basic Formula
The math is straightforward:
DTI = (Total Monthly Debt Payments ÷ Gross Monthly Income) × 100
Gross monthly income means your pay before taxes, health insurance, or retirement contributions are taken out. If you’re salaried, divide your annual salary by 12. If your income varies (freelance work, commissions, bonuses), lenders typically average two years of tax returns to find a stable monthly figure. Include all reliable income sources: wages, self-employment earnings, Social Security, disability, alimony you receive, rental income, and investment income you can document.
What Counts as a Monthly Debt Payment
This is where most people get tripped up. Lenders only count obligations that show up on your credit report or in legal records, not your full monthly budget. Here’s what goes into the calculation:
- Housing costs: your mortgage payment (or rent), property taxes, homeowners insurance, HOA fees, and any maintenance fees bundled into your housing obligation
- Credit card minimum payments: only the minimum due on each statement, not your total balance and not the amount you actually pay each month
- Installment loans: auto loans, student loans, personal loans, boat or RV loans, and any co-signed loans you’re responsible for
- Lines of credit: HELOC payments and other revolving credit line minimums
- Legal obligations: child support, alimony, court-ordered payments, and IRS installment agreements
Notice what’s missing from that list. Utilities, groceries, phone bills, streaming subscriptions, childcare costs, medical bills (unless financed through a loan), and your retirement contributions are all excluded. These expenses are real, but lenders don’t factor them into DTI. The same goes for insurance premiums you pay separately from your mortgage.
A Step-by-Step Example
Say you earn $72,000 a year. Your gross monthly income is $6,000. Each month you pay:
- Mortgage (including taxes and insurance): $1,400
- Auto loan: $350
- Student loan: $250
- Credit card minimums across two cards: $80
Your total monthly debt payments add up to $2,080. Divide that by $6,000, and you get 0.347. Multiply by 100, and your DTI is about 35%.
If you’re calculating DTI to see whether you qualify for a new loan, add the expected new payment to your current debts before dividing. If that same borrower wanted a car with a $400 monthly payment, the new total would be $2,480, pushing DTI to roughly 41%.
Front-End vs. Back-End DTI
Mortgage lenders often look at two versions of your ratio. The front-end ratio (sometimes called the housing ratio) includes only your housing costs divided by gross income. The back-end ratio includes all your monthly debts, housing and everything else. When someone refers to “your DTI” without further context, they almost always mean the back-end number, because it gives a fuller picture of your obligations.
Using the example above, the front-end ratio would be $1,400 ÷ $6,000 = 23%. The back-end ratio is the 35% we already calculated. Many conventional mortgage lenders prefer a front-end ratio at or below 28%, though this isn’t a hard cutoff.
What Lenders Consider a Good DTI
Different loan types have different thresholds, but the general ranges hold fairly steady:
- 36% or lower: considered strong by most lenders. You’ll typically qualify for the best rates and terms.
- 37% to 43%: still acceptable for many conventional mortgages, though you may face slightly tighter scrutiny or higher rates.
- 44% to 50%: some loan programs, particularly FHA and VA loans, may approve borrowers in this range if they have compensating factors like a high credit score, significant cash reserves, or a large down payment.
- Above 50%: very few lenders will approve a loan at this level. Most conventional and government-backed programs cap out around 50%.
For non-mortgage lending, the thresholds are less standardized. Credit card issuers and personal loan companies each set their own limits, but a DTI under 36% gives you the widest access to credit across the board.
How to Lower Your DTI Before Applying
Because DTI is a simple fraction, you can improve it by shrinking the top number (debt payments) or growing the bottom number (income), or both.
On the debt side, paying off a small installment loan or an extra credit card has an outsized effect. Eliminating even a $150 monthly payment drops your ratio noticeably. If you carry credit card balances, paying them down reduces your minimum payments, which is what lenders actually count. Avoid opening new credit accounts in the months before a major loan application, since even a small new payment adds to your numerator.
On the income side, a raise, a side job, or adding a co-borrower with their own income can all bring the ratio down. Keep in mind that lenders need to verify any income you claim, so freelance earnings typically require two years of tax documentation.
One detail that surprises people: paying off a loan in collections doesn’t always help your DTI immediately, because collections accounts often aren’t counted as a monthly obligation in the first place. What helps is reducing the recurring payments that show up on your credit report each month.
Running the Numbers Yourself
Pull up your most recent credit card and loan statements so you have accurate minimum payment amounts. Grab a recent pay stub for your gross income. Then plug into the formula: add every qualifying monthly payment, divide by gross monthly income, and multiply by 100. The whole exercise takes about five minutes, and it tells you exactly where you stand before a lender runs the same calculation on their end.
If you’re applying with a spouse or partner, lenders will combine both borrowers’ debts and both borrowers’ incomes into a single DTI. That can help or hurt depending on each person’s financial picture, so run the numbers jointly and individually to see which scenario works best.