Understanding Debt-to-Income Ratio
Debt-to-income ratio, or DTI, is one of the most important numbers in mortgage qualifying. Here's how it works and why it matters.
How DTI is calculated
DTI compares your total monthly debt payments to your gross monthly income. Lenders look at it to make sure your new mortgage fits comfortably alongside your existing obligations.
Worked example
If you earn $6,000 per month and your total monthly debts (including the new mortgage) would be $2,100, your DTI is 2,100 / 6,000 = 35%.
Why it shapes your budget
A lower DTI generally means more borrowing flexibility and stronger approval odds. Paying down revolving debt before applying can improve both your DTI and your credit profile.
Key takeaways
- DTI compares monthly debts to gross monthly income.
- Lower DTI usually means more flexibility.
- Reducing debt before applying can help twice: DTI and credit.
Test your knowledge
4 quick questions. Score 70% or higher to complete this lesson.
1. What does DTI compare?
2. If you earn $6,000/month and total debts would be $2,100, your DTI is:
3. A lower DTI generally means:
4. Paying down revolving debt before applying can improve:
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Written by
Joel Olson
Founder, Blueprint Home Loans LLC · Florida Mortgage Broker · Individual NMLS #1410944
Joel founded Blueprint Home Loans on an education-first philosophy: help buyers understand their options and make confident, informed decisions. With more than 20 years in financial services, his goal isn't to sell a mortgage. It's to build a plan around your life.
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This lesson is educational and is not a commitment to lend, financial advice, or a guarantee of approval. Program guidelines, rates, and eligibility vary by lender, location, and individual circumstances and change over time. Speak with a licensed mortgage professional for guidance specific to your situation.
Finished “Understanding Debt-to-Income Ratio”? Here's what's next
- Credit Scores and Your MortgageWhy: Builds on what you just read with “Credit Scores and Your Mortgage.”
- Getting Pre-Approved for a MortgageWhy: Builds on what you just read with “Getting Pre-Approved for a Mortgage.”
- Fixed vs Adjustable-Rate MortgagesWhy: Closely related reading: “Fixed vs Adjustable-Rate Mortgages.”
- How Mortgage Interest Rates WorkWhy: Closely related reading: “How Mortgage Interest Rates Work.”
Last reviewed July 2026. Educational information only, not a commitment to lend, a rate quote, or a guarantee of approval. Blueprint Home Loans LLC is licensed in Florida; loan program rules are federal and apply nationally.