Personal Finance

Debt-to-Income Ratio Calculator

Calculate your front-end and back-end DTI ratios, benchmark against the 28/36 rule, and assess mortgage qualification readiness.

Income and Debt Inputs

$

Housing Payment

$
$

Monthly Debt Payments

$
$
$
$

Front-End / Housing Ratio

25.4%

Within 28% Guideline

Back-End / Total DTI Ratio

40.9%

Approaching 43% Cap

Total Monthly Debt

$2,900

All recurring debt payments combined

Remaining Borrowing Capacity

$0

Room before hitting 36% limit

Monthly Debt Breakdown

Each debt category as a percentage of gross monthly income

CategoryMonthly Payment% of Income
Mortgage / Rent$1,80025.4%
Property Tax / Insurance$00.0%
Auto Loans$4506.4%
Credit Cards$3004.2%
Student Loans$2503.5%
Other Debts$1001.4%

Max Mortgage at 28% Rule

Maximum housing payment at your income level

$1,983

Understanding Front-End, Back-End, and the 28/36 Rule

Front-End / Housing Ratio

The percentage of gross monthly income consumed by housing costs alone, including principal, interest, taxes, insurance, and HOA fees. Lenders prefer this ratio at or below 28%.

Back-End / Total DTI Ratio

The percentage of gross monthly income consumed by all recurring debt payments combined: housing, auto loans, credit cards, student loans, and any other debt obligations. The conventional guideline caps this at 36%.

The 28/36 Rule

A longstanding mortgage lending benchmark stating that no more than 28% of gross monthly income should go toward housing costs, and no more than 36% should cover all debt payments combined.

Qualified Mortgage 43% Cap

Under the Consumer Financial Protection Bureau Qualified Mortgage rule, lenders generally cannot approve loans if the borrower back-end DTI exceeds 43%, regardless of other compensating factors.

Frequently Asked Questions

DTI Ratio Benchmark Matrix

DTI RangeLender AssessmentRecommended Action
Under 36% Back-EndHealthy / ApprovableMaintain current debt levels and monitor before major purchases
36% to 43% Back-EndCaution / Conditional ApprovalPay down revolving debt and avoid new credit applications before mortgage
Over 43% Back-EndHigh Risk / Likely DenialAggressively reduce monthly debt or increase income before applying
Over 50% Back-EndCritical Risk / Not EligibleReduce debt substantially before applying for any loan

3 Common DTI Calculation Mistakes

1

Using net (take-home) income instead of gross (pre-tax) income, which understates the DTI ratio and creates false confidence in qualification readiness.

2

Forgetting to include minimum credit card payments, child support, alimony, or other court-ordered payments in the monthly debt total.

3

Counting one-time or irregular expenses (annual insurance premiums, quarterly tax payments) as recurring monthly debt when lenders only consider fixed monthly obligations.

DTI Ratio Formulas

Front-End Ratio (%) = (Monthly Housing Cost / Gross Monthly Income) x 100
Back-End Ratio (%) = (Total Monthly Debt / Gross Monthly Income) x 100
28/36 Rule: Housing <= 28% of Gross Monthly Income AND Total Debt <= 36% of Gross Monthly Income

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