What You Will Calculate
Debt-to-income ratio (DTI) is a percentage that shows how much of your monthly gross income goes toward debt payments. Lenders use this metric to evaluate your ability to manage monthly payments and repay debts. This guide focuses on the US concept of DTI, which uses gross monthly income (before taxes) and monthly debt obligations.
The DTI Formula
DTI = (Total Monthly Debt Payments ÷ Gross Monthly Income) × 100
What Income to Include
For DTI calculation, use your gross monthly income — your income before taxes and other deductions. Include:
- Salary and wages (before tax withholdings)
- Bonuses and commissions (average monthly amount)
- Freelance or self-employment income
- Rental income
- Investment income (dividends, interest)
- Other regular income (alimony, child support, if consistent)
Important: Do not use net income (after taxes). Lenders specifically require gross income for DTI calculations.
What Debts to Include
Include all recurring monthly debt obligations:
- Mortgage or rent payments
- Car loan payments
- Credit card minimum payments
- Student loan payments
- Personal loan payments
- Alimony or child support payments
- Home equity loan payments
Do not include: Utilities, groceries, insurance premiums (unless required by lender), taxes, or other living expenses.
Step-by-Step Calculation
Add up all your income before taxes. If you receive annual income, divide by 12. If you receive variable income (commissions, freelance), use a 6-12 month average.
Include all recurring monthly debt obligations. For credit cards, use the minimum required payment, not your actual payment amount.
Divide your total monthly debt payments by your gross monthly income, then multiply by 100 to get your DTI percentage.
Compare your DTI to lender requirements. Below 36% is generally excellent, 36-42% is good, 43-50% may limit options, and above 50% typically indicates financial stress.
Practical Example
Monthly Gross Income: $6,000
Monthly Debts:
- Car loan: $450
- Credit card minimums: $150
- Student loan: $200
- Current rent: $1,200
Total Monthly Debts: $2,000
DTI = ($2,000 ÷ $6,000) × 100 = 33.3%
Result: Good DTI ratio — generally qualifies for most loan types
How to Interpret Your DTI
Different lenders have different DTI requirements, but here are general guidelines:
Below 36%
Considered healthy. You'll likely qualify for most conventional loans with competitive rates.
36% - 42%
Considered good. Most lenders will approve, though some may require compensating factors (high credit score, large down payment, strong cash reserves).
43% - 50%
May limit your options. Some lenders may approve but with higher rates or stricter terms. FHA loans may be more flexible.
Above 50%
Generally considered high risk. Most conventional loans become difficult to obtain. Focus on reducing debt or increasing income before applying.
Front-End vs Back-End DTI
When calculating DTI for mortgages, lenders may consider two versions:
Front-End DTI
Only housing-related expenses: mortgage payment (principal + interest), property taxes, homeowners insurance, and HOA fees. This shows how much of your income goes toward housing.
Back-End DTI
Includes all monthly debt obligations: housing expenses plus car loans, credit cards, student loans, and other debts. This is the primary metric lenders use for loan approval.
When calculating your own DTI, focus on back-end DTI as it reflects your complete financial picture.
Common Calculation Mistakes
Avoid these errors when calculating your DTI:
- Using net income instead of gross: Lenders specifically require gross income (before taxes)
- Forgetting minimum payments: Use credit card minimums, not your actual payment
- Missing small debts: Include all recurring monthly obligations
- Including non-debt expenses: Don't count utilities, groceries, or living expenses
- Not averaging variable income: For irregular income, use a 6-12 month average
For the complete definition of DTI and what it measures, see What Is Debt-to-Income Ratio.
Frequently Asked Questions
What income should I use for DTI calculation?
Use your gross monthly income (before taxes and deductions). This includes salary, wages, bonuses, commissions, freelance income, rental income, and other regular income. Do not use net income (after taxes).
Which debts should I include in DTI?
Include all recurring monthly debt obligations: mortgage/rent, car loans, credit card minimum payments, student loans, personal loans, and required alimony/child support. Do not include utilities, groceries, insurance premiums (unless required by lender), or living expenses.
Should I use credit card minimums or actual payments?
Use the minimum required payment on your credit card statements, not your actual payment amount. Lenders evaluate based on the minimum obligation, not your voluntary higher payments.
How do I calculate DTI for irregular income?
For variable income (commissions, freelance, seasonal work), calculate your average gross income over 6-12 months. Use this monthly average as your income figure in the DTI formula.
Does DTI affect loan approval?
Yes, DTI is a key factor in loan approval. Lenders use it to assess your ability to manage monthly payments. Lower DTI generally means better loan terms and higher approval odds, but DTI is one of several factors including credit score and payment history.