DTI Ratio Calculator
Calculate your front-end (housing) and back-end (total) debt-to-income ratios to see if you qualify for a mortgage.
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Visualization
How It Works
Debt-to-income ratio (DTI) is one of the most important numbers lenders use to determine if you can afford a mortgage. The front-end ratio measures housing costs as a percentage of gross income, while the back-end ratio includes all monthly debt obligations. Most conventional lenders want a front-end DTI under 28% and a back-end DTI under 36-43%.
The Formula
Back-End DTI = (Total Monthly Debt / Gross Monthly Income) x 100
Variables
- Front-End DTI — Housing costs (mortgage + taxes + insurance + HOA) divided by gross monthly income. Target: 28% or less
- Back-End DTI — All monthly debt payments (housing + car + student loans + credit cards + other) divided by gross income. Target: 36-43%
- 28% — Traditional maximum front-end DTI for conventional loans
- 43% — Maximum back-end DTI for most qualified mortgages (QM). FHA allows up to 50% in some cases
Worked Example
With $8,000 gross monthly income, $2,200 mortgage payment, $450 car payment, $300 student loans, and $150 credit card minimums: front-end DTI = $2,200 / $8,000 = 27.5% (good). Back-end DTI = $3,100 / $8,000 = 38.8% (acceptable for most lenders).
Practical Tips
- Pay down credit card balances and small debts before applying for a mortgage to lower your back-end DTI.
- Increasing income counts too. A raise, bonus income, or adding a co-borrower can improve your DTI ratios.
- FHA loans are more lenient, allowing back-end DTI up to 43-50% with compensating factors like cash reserves or high credit scores.
- Use gross income (before taxes), not net income. Lenders calculate DTI based on pre-tax income.
- Do not open new credit accounts or take on new debt between pre-approval and closing, as it can push your DTI over limits.
Frequently Asked Questions
What DTI do I need to qualify for a mortgage?
Conventional loans typically require a back-end DTI of 36-45%. FHA loans allow up to 43-50% with compensating factors. VA loans have no official DTI cap but most lenders prefer under 41%. The lower your DTI, the better your interest rate and loan terms will be.
What debts are included in DTI calculations?
Lenders include all minimum monthly debt payments that appear on your credit report: mortgage/rent, auto loans, student loans, credit card minimums, personal loans, child support, and alimony. Utilities, insurance premiums (unless bundled with mortgage), groceries, and subscriptions are not included.
How can I lower my DTI quickly?
The fastest way is to pay off small debts entirely (eliminating a $150/month car payment instantly reduces DTI). You can also increase your down payment to lower the mortgage amount, extend loan terms for lower payments, or add a co-borrower with income. Refinancing high-rate debt to lower payments also helps.
Does DTI affect my interest rate?
Indirectly, yes. While credit score is the primary rate driver, a higher DTI increases your risk profile. Some lenders add rate adjustments (pricing hits) for DTIs above certain thresholds. A lower DTI can also qualify you for better loan programs with lower rates.
Should I use gross or net income for DTI?
Always use gross income (before taxes and deductions). Lenders calculate DTI based on pre-tax income because tax situations vary. If you are self-employed, lenders typically use your adjusted gross income from the last two years of tax returns, which may be lower than your total revenue.
Sources
- CFPB: Debt-to-Income Ratio Explained
- Fannie Mae Selling Guide: DTI Requirements
- HUD: FHA DTI Guidelines