DTI measures debt payments against income before taxes. It helps lenders review a loan, but it does not show every expense in your household budget.
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The remaining amount is not free spending money. Taxes, groceries, utilities, savings and other expenses still need to come out.
1. DTI compares payments with income
DTI stands for debt-to-income ratio. It compares monthly debt payments with monthly income before taxes. Calculate monthly debt payments ÷ gross monthly income × 100. Use monthly payments—not the total balances you owe.
2. Use qualifying income, not take-home pay
Gross income is income before taxes and deductions. A lender decides how much of your income qualifies. Bonuses, commissions and self-employment earnings may need additional documentation. Do not assume all deposits into your bank account count as income.
3. Count the proposed housing payment and other debts
For mortgage planning, include the full proposed housing payment and applicable debt payments. These can include auto loans or leases, student loans and revolving-credit payments. Support obligations and other recurring debts may count under program rules. Ask the lender how it treats your specific accounts.
4. Housing-only versus total DTI
Housing-only, sometimes called front-end DTI, compares the qualifying housing payment with income. Total, sometimes called back-end DTI, adds counted non-housing debt payments. Label the ratio you are using so you do not compare two different measures.
5. A lower ratio is not an approval guarantee
Loan programs and lenders have different limits. They also review credit, assets, income stability and the property. Do not treat a percentage from an online calculator as an approval decision or a comfortable spending target.
6. Test a change before committing
Use the worked example below to compare housing prices and monthly debt payments. Reducing a counted payment can change DTI. Increasing qualifying income can also change it, but your lender must verify the income. Ask before paying off or changing an account during the application.
7. Keep your real-life budget separate
Groceries, utilities, healthcare and childcare still need money even when they are not part of the lender’s debt calculation. Use actual take-home pay to test your full household budget. Include maintenance and savings rather than spending every dollar that a lender might allow.
SEE THE NUMBERS
Example: $7,000 monthly gross income
| Monthly item | Amount |
|---|---|
| Full proposed housing payment | $2,000 |
| Car payment | $400 |
| Credit-card minimum payments | $100 |
| Total counted debt payments | $2,500 |
| Housing-only DTI | $2,000 ÷ $7,000 = 28.6% |
| Total DTI | $2,500 ÷ $7,000 = 35.7% |
| Total DTI if counted car payment is removed | $2,100 ÷ $7,000 = 30.0% |
Illustrative arithmetic, not an approval or payoff recommendation. The lender determines qualifying income, payment treatment and eligibility. Verify that paying off an account actually removes the counted payment before relying on the lower ratio.
Key terms, in plain English
- Gross income
- Income before taxes and deductions.
- Qualifying income
- The income a lender accepts under its loan rules.
- Housing-only DTI
- Qualifying housing payment divided by qualifying monthly income.
- Total DTI
- Qualifying housing and other counted monthly debt payments divided by income.
Common mistakes to avoid
- Dividing by take-home pay when calculating lender DTI.
- Using total loan balances instead of required monthly payments.
- Counting only mortgage principal and interest while leaving out other housing costs.
- Assuming passing a lender’s ratio means your budget is comfortable.
Questions to ask
Bring these to your lender, agent or housing counselor, as appropriate.
- Which income and debt payments are you counting?
- What is the qualifying housing payment for this loan?
- Which DTI rules apply to the program you are quoting?
- Would paying off this account change my qualifying payment?
Common questions
Is DTI part of my credit score?
DTI is a separate lending measure. A FICO Score uses credit-report information; a lender reviews income and debts separately when evaluating a mortgage.
What is a good DTI?
There is no single approval cutoff for every mortgage. Ask which program rules and lender requirements apply. A lower ratio generally leaves more room for debt payments, but still check all your living expenses.
Do I use current rent and the new mortgage together?
For a planned purchase of your primary residence, start with the proposed housing payment rather than automatically adding rent that will end. Other properties or continuing obligations can change the lender’s calculation; confirm your situation.
Your next steps
- List gross income and all monthly debt payments.
- Estimate the full proposed housing payment without double-counting costs.
- Ask the lender which payments and income qualify, then check your take-home budget.
Sources and further reading
Official resources checked October 12, 2026. Loan and program rules can change. Confirm the requirements for your own purchase.
Educational information and planning examples; not a loan offer or personalized financial advice.