What a Debt-to-Income Ratio Tells a Lender

A debt-to-income ratio (DTI) tells a lender how much of a borrower's gross monthly income is already committed to debt payments, including the new loan. A lower ratio leaves more room to absorb a drop in income or a rise in costs, and lenders use it alongside credit history, assets and the loan's price. It is a screening measure with program-specific limits, not a pass-or-fail score.

Key takeaways

DTI is monthly debt payments divided by gross monthly income. The front-end ratio counts housing only; the back-end ratio adds all other recurring debt.
There is no single limit. As of October 2026, Fannie Mae allows up to 50% through Desktop Underwriter, FHA's manual chart runs from 31/43 to 40/50, VA pairs a 41% standard with a residual income test, and USDA's regulation sets 29% for housing and 41% in total.
The federal General QM definition has had no 43% DTI cap for applications received from October 1, 2022, but lenders must still consider and verify DTI or residual income.
In the example below, paying off a $350 car payment cuts the back-end ratio from 35.7% to 31.1%. That adds $350 to the affordable housing payment under a total-only limit, but $0 under FHA's 31/43 tier, where the housing cap binds.

What the ratio measures

The Consumer Financial Protection Bureau (CFPB) defines DTI as all monthly debt payments divided by gross monthly income, meaning income before taxes and other deductions. It adds that different loan products and lenders have different DTI limits.

DTI = monthly debt payments / gross monthly income x 100

Mortgage programs split the ratio in two: the front-end (housing) ratio divides only the housing payment by income, and the back-end ratio adds every other counted debt. FHA calls them the Total Mortgage Payment to Effective Income ratio and the Total Fixed Payments to Effective Income ratio; USDA calls them the PITI and total debt ratios. Fannie Mae's published limits apply only to the total ratio.

What counts as debt and income

The housing payment

FHA's Handbook 4000.1 counts principal and interest, real estate taxes, hazard and flood insurance, mortgage insurance, association fees, ground rent, special assessments, secondary financing and other escrows. VA's regulation uses a similar list of principal, interest, taxes, insurance and assessments. A quote showing only principal and interest understates the figure a lender will use.

Other debts

Under Fannie Mae's Selling Guide B3-6-05, when the credit report shows no minimum payment on a revolving account and nothing documents a lower one, the lender must use 5% of the balance. Installment debts count if more than ten payments remain, and lease payments count however many months are left.

Student loans

This is where programs differ most. The table shows each program's published rule, with its date, for a loan whose credit report payment is $0.

Program	How a $0 reported payment is counted
Fannie Mae (B3-6-05, revised 08/05/2026)	On an income-driven plan, the lender may qualify the borrower with $0 if documents show the actual payment is $0. For deferred loans or loans in forbearance, it may use 1% of the balance or a fully amortizing payment.
FHA (Mortgagee Letter 2021-13, case numbers from August 16, 2021)	0.5% of the outstanding balance, whatever the payment status. A payment above zero on the credit report or in documentation is used as is.
USDA (HB-1-3555, Chapter 11, 2025 text)	0.5% of the balance shown on the credit report or the creditor's verification, whatever the payment status.

VA's student loan rules were not compared here; the lender's program guidance controls.

Income

Underwriting uses gross income. For self-employed borrowers, Fannie Mae generally requires a two-year history of earnings from signed tax returns or IRS transcripts, and lenders look at year-to-year trends rather than one good year.

A worked example in numbers

Illustrative example. A household has $7,500 in gross monthly income and these monthly payments: housing $1,900 (principal, interest, taxes, insurance and association fees), car loan $350, credit card minimum $150 and student loan $280.

Front-end: 1,900 / 7,500 = 25.3%
Other debt: 350 + 150 + 280 = 780
Back-end: (1,900 + 780) / 7,500 = 2,680 / 7,500 = 35.7%

The most housing each limit allows

Rearranging the formula gives the largest housing payment under a total limit: income times the limit, minus other debts. If the program also caps the housing ratio, the lower of the two results applies.

Fannie Mae manual, 36% total only:
  7,500 x 0.36 = 2,700; 2,700 - 780 = 1,920
FHA manual, 31/43 tier:
  total:   7,500 x 0.43 = 3,225; 3,225 - 780 = 2,445
  housing: 7,500 x 0.31 = 2,325
  maximum = lower of the two = 2,325

What paying off the car does

Removing the $350 car payment cuts other debt to $430 and the back-end ratio to 2,330 / 7,500 = 31.1%, down 4.7 percentage points. Under the 36% total-only limit, the maximum housing payment rises by the full $350. Under FHA's 31/43 tier, the total limit would now allow $2,795, but the 31% housing cap still stops at $2,325, so the payoff adds nothing.

Scenario	Other debt	Back-end DTI	Max housing, 36% total	Max housing, FHA 31/43
Current debts	$780	35.7%	$1,920	$2,325
Car paid off	$430	31.1%	$2,270	$2,325

How the student loan treatment moves the result

Now suppose the credit report shows $0 for the student loan and the balance is $40,000. With housing $1,900, car $350 and card $150 unchanged:

Counted at	Where it applies	Monthly amount	Back-end DTI
Documented $0	Fannie Mae, income-driven plan	$0	32.0%
0.5% of balance	FHA and USDA, any status	$200	34.7%
1% of balance	Fannie Mae, deferred or in forbearance	$400	37.3%

Depending on the program and the loan's status, the same balance moves the ratio across 5.3 percentage points, against 35.7% with the $280 billed payment. Program limits are set against gross income, so a ratio computed on take-home pay cannot be compared with them: against a hypothetical $5,900 of take-home pay, the same $2,680 would read 45.4%.

Limits by loan program

These are the published standards as of October 2026. Each applies only to the loans and underwriting method named, and lenders may set stricter rules.

Conventional loans sold to Fannie Mae

Under Selling Guide B3-6-02 (revised April 2, 2025), the maximum is 50% for loans underwritten with Desktop Underwriter. Manually underwritten loans are capped at 36%, rising to 45% when the borrower meets the credit score and reserve requirements in the Eligibility Matrix. Some transactions have lower limits, and a loan whose recalculated ratio later exceeds 45% (manual) or 50% (DU) cannot be delivered to Fannie Mae.

The federal qualified mortgage rule

A qualified mortgage (QM) is presumed to meet the federal ability-to-repay rule: conclusively for loans that are not higher-priced, rebuttably for higher-priced ones. The General QM definition in Regulation Z section 1026.43(e)(2) used to cap DTI at 43%. For applications from October 1, 2022, it caps price instead: for larger first-lien loans, the annual percentage rate must be less than 2.25 percentage points above the average prime offer rate, with higher spreads allowed for smaller loans. The creditor must still consider and verify income or assets, debts, alimony, child support and DTI or residual income. A General QM also cannot have negative amortization, interest-only or balloon payments, a term over 30 years, or points and fees above set caps. FHA, VA and USDA loans follow their agencies' own QM definitions.

FHA loans

For manually underwritten FHA loans, Handbook 4000.1 section II.A.5.d.viii sets housing and total ratios by credit score and compensating factors. HUD reproduced the current chart in Mortgagee Letter 2026-11 (October 8, 2026), which changes only the chart's wording.

Minimum decision credit score	Maximum ratios (housing / total)	Compensating factors
500-579 or no credit score	31% / 43%	Not applicable
580 and above	31% / 43%	None required
580 and above	37% / 47%	One: cash reserves, minimal increase in housing payment, or residual income
580 and above	40% / 40%	No discretionary debt
580 and above	40% / 50%	Two of: reserves, minimal payment increase, significant additional income, residual income

Energy-efficient homes in the 31/43 tiers may stretch to 33/45. The chart covers manual underwriting only, not automated scorecard approvals.

VA loans

VA's regulation, 38 CFR 36.4340, sets a 41% standard and also requires a residual income test: what is left each month for living expenses after shelter costs and other obligations, measured against VA guidelines. A ratio above 41% can still be approved with a justification signed by the underwriter's supervisor, which is not needed when residual income exceeds the guideline by at least 20%.

USDA guaranteed loans

USDA's regulation, 7 CFR 3555.151(h), sets a 29% housing (PITI) ratio and a 41% total debt ratio, which can be exceeded with compensating factors and either written USDA approval or acceptance by USDA's automated system. A two-year exception in Procedure Notice 621 (August 5, 2024) had raised the housing limit to 34%, but USDA returned it to 29% for applications with a final GUS submission on or after November 4, 2025. Under USDA's September 2025 notice, a higher housing ratio needs a GUS Accept recommendation or a waiver capped at 32%, with credit scores of 680 or higher for all applicants and a documented compensating factor.

What the evidence says about risk

Higher ratios have gone with more early trouble. In its 2020 General QM final rule, the CFPB used "early delinquency" (60 or more days past due within the first two years) as a proxy for ability to repay. Among 2018 first-lien purchase loans, observed only through December 2019, early delinquency rose from 0.4% at a DTI of 25% or less to 0.5% (26-35%), 0.7% (36-43%) and 0.9% (44-50%). Among 2002-2008 loans it ran from 3% to 9% at 61-70%.

Price separated loans more sharply: from 0.2% for 2018 loans priced at or below the average prime offer rate to 4.2% for loans 2 or more points above it. The bureau concluded that a loan's price, which reflects many factors including DTI, may be a more holistic measure of ability to repay than DTI alone. DTI also leaves out savings, living costs that are not debts and how secure the income is, which is why programs add compensating factors, reserves and, for VA, a residual income test.

How to lower the ratio

Remove a payment, not just a balance. Paying off an installment loan deletes its payment, unless the lender already excludes it (see the FAQ on debts with few payments left). Paying down a card helps only if the counted minimum falls.
Check which limit binds. If a program's housing cap is the tighter limit, as in the FHA example, cutting other debt lowers the ratio without raising the payment you can qualify for.
Shrink the new payment. A smaller loan, a lower rate or a different term changes the housing payment that goes into both ratios.
Watch the reserve trade-off. FHA lists cash reserves as a compensating factor, so draining savings to clear a debt can swap one strength for another.

Frequently asked questions

Does a debt with only a few payments left still count?

Under Fannie Mae's rules, installment debt with more than ten monthly payments remaining must be included. A debt with fewer payments can still be included if it significantly affects the borrower's ability to meet credit obligations, so paying off a nearly finished loan may not change the counted ratio. Lease payments always count.

Do child support and alimony count?

Under Fannie Mae's B3-6-05, payments required by a divorce decree, separation agreement or other written legal agreement count as monthly debt if they continue for more than ten months. Voluntary payments do not. For alimony, the lender may instead reduce qualifying income by the payment amount.

How does a non-occupant co-borrower change the limits?

For Fannie Mae manually underwritten loans, the maximum is lower than 45% for the occupying borrower when there is a non-occupant borrower. For FHA, the ratios for borrowers with no credit score use only the income of borrowers who occupy the property and are obligated on the mortgage.

Is DTI used only for mortgages?

No. The CFPB describes DTI as one way lenders measure a borrower's ability to manage payments on money they plan to borrow. The mortgage limits in this guide do not carry over to auto loans, personal loans or cards.

Does meeting the DTI limit guarantee approval?

No. VA's regulation states that meeting both the ratio and residual income standards does not make a loan automatically approved; the lender must also judge credit and compensating factors. Other programs likewise weigh credit history, verified income and assets.

A checklist before you apply

Write down gross monthly income from pay records or tax returns, noting variable pay and years of self-employment.
List every recurring debt from credit reports and statements, with the minimum payment, the balance and the payments left.
Price the housing payment with taxes, insurance, mortgage insurance and association fees included.
Compute both ratios, counting each student loan the way the target program does.
Find the highest housing payment under the total and the housing limit, and check which binds before paying off a debt.
Ask the lender which program rules apply. The Loan Calculator can help with the payment arithmetic.