To calculate your debt-to-income ratio for a mortgage, add up every recurring monthly debt payment, including the proposed housing payment, and divide that total by your gross monthly income. Multiply by 100 to get a percentage. Most conventional lenders will approve a back-end ratio between 36 and 50 percent depending on how the loan is underwritten, and government-backed programs set their own limits. Running the math yourself before you apply tells you where you stand and what price range is realistic.
A quick example. Say you earn $6,000 per month before taxes. Your expected mortgage payment (with taxes and insurance) is $1,800, and you have $700 in other monthly debt payments. Your total monthly debt is $2,500. Divide $2,500 by $6,000, and your DTI is about 42 percent.
Step 1: Figure Out Your Gross Monthly Income
The income side uses gross monthly income, meaning what you earn before taxes, retirement contributions, and other paycheck deductions. If you’re salaried, divide your annual salary by twelve. If you’re hourly with a steady schedule, multiply your hourly rate by your typical weekly hours, then by 52, and divide by twelve.
Overtime, bonuses, and commissions count if you can document a track record. Fannie Mae recommends at least two years of receiving variable income, though twelve to twenty-four months may be acceptable when other factors support the shorter history.1Fannie Mae. General Income Information W-2s from the past two years and recent pay stubs are the usual documentation.2Fannie Mae. Base Pay (Salary or Hourly), Bonus, and Overtime Income
Social Security benefits, pensions, disability income, and alimony or child support also count. Income with a set end date, like alimony or child support, has to be shown continuing for at least three years from the mortgage date.1Fannie Mae. General Income Information Pension and Social Security income generally have no expiration requirement.
Grossing Up Nontaxable Income
If part of your income is nontaxable, such as certain Social Security benefits or disability payments, lenders can increase that figure by up to 25 percent to reflect its higher purchasing power. If you receive $2,000 per month in nontaxable disability income, the lender could count it as $2,500. For Social Security, 15 percent of the benefit is automatically treated as nontaxable; grossing up more requires documentation showing the additional amount is also tax-free.3Fannie Mae. FAQ: Top Trending Selling FAQs
Self-Employment Income
Self-employed borrowers, generally anyone with 25 percent or more ownership in a business, provide federal tax returns, and lenders average the net income over the most recent one to two years.1Fannie Mae. General Income Information Because returns reflect deductions, lenders add back non-cash expenses like depreciation and amortization that reduced taxable income but didn’t cost cash. That adjustment can meaningfully increase qualifying income for owners whose returns understate real cash flow.
Rental Income
If you own a rental, lenders don’t count the full rent. Fannie Mae multiplies gross monthly rent by 75 percent, with the other 25 percent assumed to cover vacancies and maintenance.4Fannie Mae. Rental Income Rent of $2,000 becomes $1,500 in the DTI calculation.
Step 2: Add Up Your Monthly Debts
The debt side captures recurring obligations that appear on your credit report or are legally required. Lenders pull a merged credit report from the three major bureaus to identify them:
- Auto loans, student loans, and personal loans, at the scheduled monthly payment.
- Credit cards, at the minimum payment listed on your statement, not the full balance.
- Child support and alimony, at the court-ordered amount.
- Any other installment debt with a fixed schedule, including medical payment plans that show up on your credit report.
Everyday living costs stay out of the calculation. Utilities, groceries, cell phone bills, car insurance, health insurance premiums, and streaming subscriptions don’t count. Lenders assume flexible costs get covered by whatever income remains after debt payments.
How Student Loans Are Counted
Student loans are treated differently by loan type, and the difference can decide whether you qualify. On a Fannie Mae conventional loan, if you’re on an income-driven repayment plan and your documented monthly payment is $0, the lender can use that $0 figure as long as you can prove it.5Fannie Mae. Monthly Debt Obligations That’s a real advantage for borrowers with large balances and low required payments.
FHA is stricter. Even with a $0 IDR payment, FHA guidelines require the lender to use 0.5 percent of the outstanding student loan balance as the assumed monthly payment. On a $60,000 balance, that’s $300 added to your DTI regardless of what you actually pay.
Step 3: Calculate Both Ratios
Lenders look at two versions of DTI. Both use the same income figure in the denominator; the difference is what goes on top.
Front-End Ratio (Housing Only)
The front-end ratio isolates the proposed housing payment. Add every component:
- Principal and interest on the mortgage.
- Property taxes, annual bill divided by twelve.
- Homeowners insurance, annual premium divided by twelve.
- Mortgage insurance, either PMI on conventional loans with less than 20 percent down, or the FHA mortgage insurance premium on FHA loans.
- HOA dues, if any.
That total is often called PITI (principal, interest, taxes, insurance). Divide by gross monthly income and multiply by 100.6Fannie Mae. Monthly Housing Expense for the Subject Property Housing costs of $1,800 on $6,000 of income give you a 30 percent front-end ratio.
Back-End Ratio (All Debts)
The back-end ratio adds every other monthly debt to that housing total and divides by gross income. In the earlier example, $1,800 in housing plus $700 in other debts equals $2,500, or about 42 percent on $6,000 of income. Lenders weigh the back-end ratio more heavily because it captures your full monthly picture.7Fannie Mae. Debt-to-Income Ratios
DTI Limits by Loan Program
Each program sets its own ceiling, and the number you’ll hear quoted depends on how the file is underwritten.
Conventional (Fannie Mae and Freddie Mac)
For manually underwritten conventional loans, Fannie Mae caps back-end DTI at 36 percent, stretching to 45 percent when the borrower meets higher credit score and cash reserve requirements in the eligibility matrix. Loans run through Fannie Mae’s automated Desktop Underwriter allow up to 50 percent, though that level requires strong compensating factors like excellent credit and significant savings.7Fannie Mae. Debt-to-Income Ratios
FHA
FHA loans typically allow a back-end DTI up to 43 percent. With compensating factors such as strong credit, additional income, or substantial savings, that can extend to 50 percent when the loan gets automated approval through the FHA TOTAL Mortgage Scorecard.
VA
VA loans don’t set a hard DTI cap, but 41 percent is the benchmark. Above that, the lender applies closer scrutiny to your residual income, which is what’s left each month after paying the mortgage, taxes, insurance, and all other debts. VA sets minimum residual income thresholds that vary by region, family size, and loan amount, and if your DTI exceeds 41 percent, you generally need at least 20 percent more residual income than the standard minimum.
USDA
USDA guaranteed rural housing loans look for a front-end ratio of 29 percent or lower and a back-end ratio of 41 percent or lower. Strong compensating factors may push the back-end limit to around 44 percent.
Jumbo
Jumbo loans exceed conforming limits, so each lender sets its own DTI standards. Many cap the back-end ratio at 43 percent, and keeping it below 36 percent strengthens the application. Higher credit scores, larger down payments, and significant reserves are typically expected alongside a lower DTI.
How to Lower Your DTI Before You Apply
If the number you just calculated is too high for the program you want, you have a few practical moves.
Pay Down or Pay Off Existing Debts
Eliminating a monthly payment removes it from your DTI entirely. Target debts with a high monthly payment relative to remaining balance. A car loan with $350 monthly payments and only $2,000 left delivers more DTI relief per dollar than paying down a large student loan balance. Fannie Mae also lets installment debts with ten or fewer payments remaining be excluded from DTI, so you don’t necessarily have to zero them out.8Fannie Mae. Debts Paid Off At or Prior to Closing
For revolving debt like credit cards, paying the balance to zero at or before closing removes that minimum payment from your DTI. You don’t have to close the account.8Fannie Mae. Debts Paid Off At or Prior to Closing
Increase Your Qualifying Income
Because DTI is a ratio, raising the denominator helps as much as cutting the numerator. If you’ve been earning overtime or bonuses consistently, make sure you have at least twelve months of documentation so the lender can count it.2Fannie Mae. Base Pay (Salary or Hourly), Bonus, and Overtime Income Adding a co-borrower whose income goes on the application raises the combined denominator and lowers the ratio.
Buy a Less Expensive Home
A lower purchase price means a smaller PITI, which reduces both ratios directly. Even a modest price cut can move your DTI under a threshold that unlocks better loan terms.
Extend the Loan Term
A 30-year mortgage produces a smaller monthly payment than a 15-year mortgage on the same loan amount. If your DTI is borderline, the longer term brings it down, though you’ll pay more interest over the life of the loan.
Avoid New Debt Between Pre-Approval and Closing
Opening a new credit card, financing furniture, or taking on a car loan after pre-approval adds to your monthly obligations and can push you past the limit. Lenders re-pull credit shortly before closing, and any new debt will show.