Debt-to-Income Ratio Calculator
Calculate current and proposed debt-to-income ratios from gross monthly income, debts, housing, and new debt.
Debt-to-Income Ratio Calculator Inputs
Results computed instantly — your data never leaves your device.
Live Debt-to-Income Ratio Calculator Results
Real-TimeProposed DTI (%)
233.3%
Proposed DTI is above the 36% reference line.
Current DTI (%)
225.0%
Monthly Debt
$13,500
Headroom to 36%
0.0%
Proposed DTI is above the 36% reference line.
How to Use the Debt-to-Income Ratio Calculator
- 1
Enter gross monthly income before deductions.
- 2
Enter existing monthly debt payments and housing payment.
- 3
Add any proposed new monthly debt.
- 4
Review current DTI, proposed DTI, and the displayed headroom to the 36% reference line.
Formula & Mathematical Basis
Variable Key
DebtExisting monthly debt payments
HousingMonthly housing payment
New DebtProposed new monthly debt payment
Gross IncomeGross monthly income before deductions
📝 The model reports one decimal place and clamps non-finite or negative inputs to safe non-negative values.
Step-by-Step Examples
Current and proposed ratio
Scenario: $6,000 gross monthly income, $1,500 housing, $1,000 existing debt, and $500 proposed debt.
- 1.Current monthly obligations = $1,000 + $1,500.
- 2.Proposed obligations add the new $500 payment.
- 3.Divide each total by $6,000.
- 4.Multiply by 100 to display percentages.
Zero-income guard
Scenario: Income is entered as zero.
- 1.The denominator is zero.
- 2.The formula returns 0% by guard.
- 3.No runtime division error is shown.
- 4.Enter gross income to restore a meaningful ratio.
Practical Use Cases
- ✓ Estimate the effect of a new monthly obligation.
- ✓ Compare current and proposed obligations.
- ✓ Communicate monthly debt assumptions.
- ✓ Check a simple reference threshold.
- ✓ Avoid divide-by-zero output.
Common Pitfalls
- ⚠ Using take-home pay instead of gross income.
- ⚠ Omitting housing or recurring debt payments.
- ⚠ Treating a reference percentage as an approval guarantee.
- ⚠ Ignoring taxes, insurance, or lender-specific definitions.
- ⚠ Entering annual income in a monthly field.
Frequently Asked Questions
How is DTI calculated?
DTI is monthly debt obligations divided by gross monthly income, multiplied by 100.
What is proposed DTI?
Proposed DTI adds the entered new debt payment to existing debt and housing before dividing by gross monthly income.
What does the 36% line mean here?
The dashboard uses 36% as a displayed planning reference. Actual underwriting standards vary by product, lender, borrower, and documentation.
What if income is zero?
The calculator returns 0% instead of dividing by zero; enter a valid gross monthly income for a meaningful ratio.
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