What is the difference between front-end and back-end DTI?

Front-end DTI counts only your housing costs (mortgage or rent, property tax, insurance, HOA) as a percentage of gross monthly income — lenders often want this at or below 28%. Back-end DTI adds all other monthly debt payments (car loans, student loans, credit card minimums, personal loans) — this is the number most lenders weigh most heavily, with 36-43% as the common ceiling.

What counts as debt in a DTI calculation?

Include recurring monthly debt obligations: mortgage or rent, minimum credit card payments, auto loans, student loans, personal loans, and court-ordered payments like alimony or child support. Do not include utilities, groceries, insurance premiums (other than those escrowed with a mortgage), taxes withheld, or discretionary spending like streaming subscriptions.

Debt-to-Income (DTI) Ratio Calculator

See your front-end and back-end DTI, how you stack up against the 28/36 and 43% mortgage rules, and how much borrowing room you have left.

DTI Calculator📅 Updated for 2026⚡ Instant results🔒 No sign-up required

💵Income & Debts

Gross Annual Income

$20,000$500,000

$7,500 gross per month

Monthly Housing Payment

$0$10,000

Rent/mortgage + tax + insurance + HOA

Other Monthly Debt Payments

$0$10,000

Car, student, personal loans + card minimums

Where You Stand

Front-end DTI (housing only)24.0%

Guideline: 28% (marker)

Back-end DTI (all debts)32.7%

Guideline: 36% (marker)

What This Calculator Does

Your debt-to-income (DTI) ratio is the single most important number lenders use to decide how much they'll let you borrow. It compares your total monthly debt payments to your gross monthly income.

This calculator computes both the front-end ratio (housing costs only) and the back-end ratio (all debts), rates your standing against standard lender guidelines, and tells you how much additional monthly debt you could take on while staying within the 36% and 43% thresholds.

Formula

Back-end DTI = (Housing + Other Debt) ÷ Gross Monthly Income × 100

Lenders compare this ratio to the 28/36 rule (28% front-end, 36% back-end) and the 43% Qualified Mortgage ceiling.

HousingMortgage/rent + property tax + insurance + HOA

Other DebtCar, student, personal loans + card minimums

GrossMonthly income before taxes and deductions

Examples

Example: $90,000 salary, $1,800 housing, $650 other debt

Gross monthly income = $7,500. Front-end = 1,800 ÷ 7,500. Back-end = 2,450 ÷ 7,500.

Front-end DTI ≈ 24% and back-end DTI ≈ 32.7% — comfortably within the 28/36 guideline.

Example: same income, $2,300 housing, $1,200 other debt

Back-end = 3,500 ÷ 7,500.

Back-end DTI ≈ 46.7% — above the 43% QM ceiling, so most lenders would decline or require compensating factors.

Frequently Asked Questions

What is a good debt-to-income ratio?+

Most lenders prefer a back-end DTI of 36% or lower; 43% is the typical maximum for a Qualified Mortgage. Under 36% is healthy, 36-43% is manageable, and above 43% makes new credit harder to obtain.

What's the difference between front-end and back-end DTI?+

Front-end DTI counts only housing costs against gross income (lenders often want ≤28%). Back-end DTI adds all other debt payments — the figure lenders weigh most, with 36-43% as the common ceiling.

What counts as debt?+

Mortgage/rent, minimum credit card payments, auto loans, student loans, personal loans, and court-ordered payments like child support. Exclude utilities, groceries, insurance, and discretionary spending.

Does DTI use gross or net income?+

Gross income — your pay before taxes and deductions. A $90,000 salary is $7,500 gross per month.