Debt-to-Income Ratio Calculator

Enter gross monthly income before tax: $7,500. For a purchase, enter the proposed housing payment, not your current rent: principal, interest, property tax, homeowners insurance, mortgage insurance and any HOA dues. Here that is $1,800.

Enter each other required payment: a $450 auto loan, a $300 student loan and $150 of credit card minimum payments, with $0 of other debt. Use the minimum payment on your statement for cards, not what you usually pay.

The results read: total monthly debt $2,700, back-end DTI 36.0%, front-end DTI 24.0%, category Healthy, and room to 36% back-end DTI $0. That last line matters: any new monthly payment, even a $50 one, moves this household into the next band.

Total Monthly Debt = Housing + Auto Loan + Student Loan + Credit Card Minimums + Other Debt

Front-End DTI = Housing Payment ÷ Gross Monthly Income × 100

Back-End DTI = Total Monthly Debt ÷ Gross Monthly Income × 100

Room to 36% = the larger of zero and (Gross Monthly Income × 0.36 − Total Monthly Debt)

Category is set by back-end DTI alone: Healthy at 36% or below, Manageable above 36% up to 43%, Stretched above 43% up to 50%, and High Risk above 50%. These bands are the calculator's own summary labels. They echo common cut-offs but are not any single program's rule, so read the loan-type limits below before drawing a conclusion. If income is zero, both ratios return 0 rather than an error.

Take $6,000 of gross monthly income, a $2,040 proposed housing payment, a $180 student loan and $120 of card minimums. Total monthly debt is $2,340. Front-end DTI is 34.0% and back-end DTI is 39.0%, which the calculator labels Manageable.

Most of this household's debt is the house itself, so the two ratios sit close together. That shape is exactly where program rules diverge:

• FHA, manual underwriting: 34.0% is over the 31% housing limit that applies with no compensating factors, even though 39.0% is under the 43% total limit. With a credit score of 580 or higher and one documented compensating factor, the 37/47 tier covers both ratios.
• VA: there is no front-end test. 39.0% is inside the 41% standard.
• Conventional (Fannie Mae): the Selling Guide states its maximum as a total ratio. 39.0% is above the 36% manual-underwriting base but inside the 45% ceiling available with the required credit score and reserves, and inside the 50% maximum for loans run through Desktop Underwriter.

For contrast, a household on $3,200 a month with a $1,100 housing payment and $760 of other debt has $1,860 of monthly debt, a 34.4% front-end ratio and a 58.1% back-end ratio: High Risk, and above every published maximum listed in the next section.

Conventional loans sold to Fannie Mae. Selling Guide B3-6-02 (published 2 April 2025) caps total DTI at 36% for manually underwritten loans, allowing up to 45% when the borrower meets the credit score and reserve requirements, and at 50% for loans underwritten through Desktop Underwriter.

FHA loans. HUD Handbook 4000.1, section II.A.5.d, sets manual-underwriting ratios as housing/total: 31/43 with no compensating factors, 37/47 with one, and 40/50 with two or more, for borrowers with a credit score of 580 or higher. Borrowers scoring 500-579, or with no credit score, stay at 31/43. These caps govern manual underwriting; loans approved through FHA's automated scorecard are assessed differently.

VA loans. 38 CFR 36.4340 sets a total DTI standard of 41% or less, alongside a separate residual-income test. A ratio above 41% can still be approved with a written justification, and that extra review is not required when residual income exceeds the VA guideline by at least 20%.

The old 43% Qualified Mortgage cap. Regulation Z's General Qualified Mortgage definition once required DTI of 43% or less. The CFPB's December 2020 final rule replaced that limit with price-based thresholds, mandatory for applications received from 1 October 2022, while still requiring lenders to consider DTI or residual income. A 43% figure you see quoted as a legal ceiling is out of date.

The familiar 28/36 rule (28% front-end, 36% back-end) is a budgeting rule of thumb, not a requirement of any of these programs.

Fannie Mae's guide builds the monthly obligation from the housing payment on the new home, installment debts with more than ten months of payments left, revolving account payments, lease payments whatever their remaining term, alimony or child support running more than ten months, and other recurring obligations.

Utilities, phone and internet bills, groceries, subscriptions and income tax are not debts, and they do not go into this calculator. Neither does insurance other than the homeowners and mortgage insurance already inside the housing payment.

401(k) loans are the common trap. Selling Guide B3-6-05 (published 5 August 2026) says a lender is not required to count a loan secured by a financial asset, such as a 401(k), as a recurring monthly obligation, provided the collateral is documented. Add a $250 401(k) loan repayment to the second example as "other debt" and back-end DTI jumps from 39.0% to 43.2%, moving it from Manageable to Stretched for a payment the lender may ignore. FHA and VA have their own rules, so confirm with the lender how they will treat it.

The calculator divides the payments you enter by the income you enter. It does not decide which income a lender will accept: bonus, overtime, self-employment and rental income each have documentation and averaging rules. It does not calculate the mortgage payment itself, the VA residual-income test, credit score effects, reserves or any other compensating factor.

It uses gross income, so two households with the same DTI can have very different take-home pay after tax, childcare and healthcare. A joint application combines both borrowers' income and debts; enter household totals if that is your situation.

Treat the category label as a quick read, not a verdict. Anyone near a program limit should ask a lender for a pre-approval rather than rely on this estimate.

To turn a target ratio into a purchase price, the home affordability calculator works backwards from income, and the mortgage calculator produces the housing payment to enter here. When card balances are what push the back-end ratio up, the credit card payoff calculator shows how fast a balance and its minimum payment can disappear, and the debt payoff calculator compares avalanche and snowball orders across several debts. Renters can apply the same logic to a lease with the rent affordability calculator.