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Debt-to-Income (DTI) Calculator

Check your front-end and back-end debt-to-income ratios against the standard 28/36 lender guideline before you apply for a mortgage.

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Income before taxes and deductions, for all borrowers on the loan.

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Your new (or current) total monthly payment: principal, interest, property tax, insurance, PMI, and HOA.

$

Minimum payments on car loans, student loans, credit cards, personal loans, child support, etc. (not utilities or groceries).

Front-end DTI (housing only)22.50%Guideline: ≤ 28%
Back-end DTI (all debt)30.00%Guideline: ≤ 36%

Your back-end DTI is within the conventional "28/36 rule" guideline of 36% — a comfortable starting point for most conventional lenders.

How this calculator works

Lenders use two related debt-to-income (DTI) ratios to judge whether a proposed mortgage payment is affordable relative to your income. Front-end DTI looks only at housing costs:

Front-end DTI = Proposed housing payment ÷ Gross monthly income

Back-end DTI is broader, adding in every other recurring monthly debt obligation you carry:

Back-end DTI = (Proposed housing payment + Other monthly debts) ÷ Gross monthly income

Both are always calculated against gross (pre-tax) monthly income, and both are expressed as a percentage. The classic guideline for these — often called the "28/36 rule" — caps front-end DTI at 28% and back-end DTI at 36%, though real underwriting is more flexible than that in practice.

Worked example

Consider a borrower with $8,000 gross monthly income, a proposed housing payment of$1,800, and $600 in other monthly debts (a car payment and a couple of credit cards). Front-end DTI works out to 22.5% ($1,800 ÷ $8,000) — comfortably under the 28% guideline. Back-end DTI works out to 30% (($1,800 + $600) ÷ $8,000) — also under the 36% guideline, and well under the roughly 45% stretch range some lenders allow with strong compensating factors. This borrower has meaningful room within standard lending guidelines.

What affects your result

  • Gross income — using pre-tax income (not take-home pay) is the standard lenders use; adding a co-borrower's qualifying income lowers your ratio.
  • The size of the proposed housing payment — a larger down payment, lower rate, or cheaper home directly lowers your front-end DTI.
  • Other recurring debts — paying down or paying off a car loan, personal loan, or credit card balance lowers your back-end DTI without touching the mortgage itself.
  • Compensating factors — a strong credit score, significant cash reserves, or a low loan-to-value ratio can let some lenders approve a higher back-end DTI than the standard 36% guideline.

A note on accuracy

This calculator applies the standard front-end/back-end DTI formulas against the conventional 28/36 guideline, with the roughly 45% figure shown as context for the higher end of what some lenders will accept with compensating factors — not as a guaranteed approval threshold. Actual underwriting standards vary by lender, loan program (conventional, FHA, VA, USDA), and individual file. For official consumer guidance on qualifying for a mortgage, see theConsumer Financial Protection Bureau.

Frequently asked questions

What is my debt-to-income ratio?

Your debt-to-income (DTI) ratio is the percentage of your gross (pre-tax) monthly income that goes toward debt payments. Lenders calculate two versions: front-end DTI (just your proposed housing payment divided by income) and back-end DTI (your housing payment plus all other monthly debts, divided by income). Enter your income, proposed payment, and other debts above to see both.

What DTI do I need for a mortgage?

The classic "28/36 rule" is the conventional guideline: front-end DTI at or below 28%, and back-end DTI at or below 36%. In practice, many conventional and FHA lenders will approve back-end DTI up to roughly 45% (sometimes higher) with compensating factors like a strong credit score, cash reserves, or a low loan-to-value ratio. The 28/36 rule is a conservative starting point, not a hard legal limit.

How do I calculate my debt-to-income ratio?

Add up your proposed housing payment (principal, interest, taxes, insurance, PMI, and HOA if applicable) plus the minimum monthly payments on all your other debts (car loans, student loans, credit cards, personal loans, and similar). Divide that total by your gross monthly income (before taxes), then multiply by 100 to get a percentage. That is your back-end DTI. Front-end DTI is the same calculation using only the housing payment.

What counts as 'debt' in the back-end DTI calculation?

Recurring, contractual monthly debt obligations: your housing payment, auto loans, student loans, minimum credit card payments, personal loans, and things like court-ordered child support or alimony. It does not typically include utilities, groceries, insurance premiums unrelated to the home, or subscription services — lenders are looking at contractual debt, not general living expenses.

What if my DTI is too high to qualify?

You generally have three levers: increase your income (or add a co-borrower), pay down or pay off existing debts to lower your monthly obligations, or reduce the proposed housing payment (smaller loan, larger down payment, or a lower rate). Even a modest reduction in a revolving balance or an extra bit of documented income can move your back-end DTI back under a lender's threshold.

Related calculators

Home Affordability CalculatorSee how much house you can afford using the 28/36 rule.Closing Cost EstimatorBudget for the upfront costs due at closing.Mortgage CalculatorEstimate your full monthly PITI payment to plug into this calculator.