Debt-to-Income Ratio Calculator,
the number lenders look at first.

Lender guide

What the DTI ratio actually means and why it matters.

Your debt-to-income ratio (DTI) is a single percentage that compares your total monthly debt obligations to your gross monthly income before taxes. It is the single most important number mortgage lenders examine when deciding whether to approve your loan and at what interest rate. A lower DTI signals financial capacity and reduces the lender’s risk; a higher DTI raises it.

Unlike your credit score, which reflects how reliably you pay, the DTI ratio answers a different question: even if you pay everything on time, is there enough income left over to handle a new loan? A borrower with a perfect 800 credit score and a 55% DTI will be declined on most conventional programs. A borrower with a 680 score and a 28% DTI will typically sail through.

Front-end DTI vs. back-end DTI

Lenders calculate two separate ratios, each serving a distinct purpose:

• Front-end DTI (housing ratio): measures only your proposed housing costs as a percentage of income. This includes principal and interest (P&I), property taxes, homeowner insurance, HOA dues, and PMI if applicable. The acronym used by underwriters is PITI (principal, interest, taxes, insurance). Most conventional lenders want this at or below 28%; FHA allows up to 31%.
• Back-end DTI (total DTI): adds every other monthly debt obligation on top of the housing costs: car loans, student loans, credit card minimum payments, personal loans, and any other recurring liability that appears on your credit report. This is the ratio most lenders emphasize and the one shown as the headline figure in this calculator. The conventional threshold is 36%; FHA and most lenders allow up to 43%; automated underwriting systems (Fannie Mae DU / Freddie Mac LP) can approve up to 45–50% with compensating factors.

The DTI formulas

Both formulas use gross income: your income before federal, state, and payroll taxes. Include all verifiable income sources: wages, self-employment income (typically averaged over two years), rental income, alimony or child support received, retirement distributions, and investment income. Do not include tips or bonus income unless it is consistent and documentable.

DTI thresholds by loan program

Different loan programs draw the line at different points. Here are the key thresholds for 2024–2025:

What counts as monthly debt?

Include all minimum required payments that appear on your credit report or can be verified by an underwriter:

• Mortgage or rent (the proposed payment, not current rent if buying)
• Auto loans and leases
• Student loans (minimum payment, or 1% of balance if in deferment)
• Credit card minimum payments (not the full balance, just the minimum due)
• Personal loans and lines of credit
• Child support and alimony obligations
• Co-signed loan payments you are legally obligated to pay

Do not include: utility bills, subscription services, groceries, insurance premiums (except homeowner insurance as part of PITI), or medical bills not on a payment plan visible to lenders.

What is a good DTI ratio?

There is no universally "good" DTI — the threshold depends on the loan type, lender, and your compensating factors. As a practical guide:

• ≤ 20% back-end: Excellent — well below every program limit; strong approval likelihood.
• 21–36%: Good — qualifies comfortably for conventional loans at competitive rates.
• 37–43%: Fair — qualifies for FHA and many conventional programs; may face higher rates or need reserves.
• 44–50%: High — limited to FHA or VA with compensating factors (large reserves, high credit score, low loan-to-value).
• > 50%: Too high — most programs decline; lenders view this as overextended regardless of credit score.

How to lower your DTI ratio

There are only two levers: reduce monthly debt payments or increase gross income. In practice:

• Pay off high-balance revolving debt first. Credit card minimum payments drop quickly when balances fall, and the positive credit utilization effect also boosts your score.
• Pay off installment loans. If a car loan has 10 or fewer payments remaining, some lenders will exclude it from the DTI calculation entirely.
• Avoid taking on new debt before closing. A new car payment in the 90 days before a mortgage application can sink an otherwise clean file.
• Increase your down payment. A larger down payment reduces the loan amount, which reduces the P&I payment, which reduces both front- and back-end DTI.
• Add a co-borrower. Adding a spouse or partner with income and no additional debts can increase the denominator significantly.
• Document all income sources. Rental income, freelance work, or a part-time job can all count if properly documented for two years.

DTI vs. credit score: what lenders weigh more

A common misconception is that a high credit score can compensate for a high DTI. In reality, DTI and credit score are evaluated largely independently. Credit score determines willingness to repay (payment history, utilization, length of history). DTI determines capacity to repay. Both must pass their respective thresholds.

Automated underwriting systems like Fannie Mae’s Desktop Underwriter (DU) evaluate the full picture holistically. A borrower with a 780 score, 12 months of cash reserves, and strong employment history might receive a DU approval at 45% DTI. The same DTI with a 650 score and minimal reserves will very likely get a DU “refer”, meaning it goes to manual underwriting and faces much tighter scrutiny.

Worked example

Gross monthly income: $7,000. Monthly obligations: mortgage $1,800, property tax $200, insurance $100, car loan $400, student loan $250, credit card minimums $100.

• Total housing (front-end): $1,800 + $200 + $100 = $2,100
• Front-end DTI: $2,100 / $7,000 = 30% (within FHA’s 31% limit)
• Total back-end: $2,100 + $400 + $250 + $100 = $2,850
• Back-end DTI: $2,850 / $7,000 ≈ 40.7% (within FHA’s 43% limit)

This borrower qualifies for FHA and potentially for a DU/LP conventional approval, but not for conservative conventional underwriting at 36% back-end. To reach the conventional 36% limit they would need to reduce monthly debts by about $310/mo or increase gross monthly income to roughly $7,900.

Disclaimer

This calculator is for educational purposes only and does not constitute financial, lending, or legal advice. Actual lender guidelines vary by institution, loan type, geographic area, and individual underwriter discretion. Consult a licensed mortgage professional before making borrowing decisions.