Debt-to-Income Ratio Calculator
The Number Lenders Check Before Your Credit Score
Debt-to-income ratio, not credit score, is often the first filter a mortgage or auto lender applies, because it measures something a credit score can't: how much of your income is already spoken for before you take on a new obligation. It's a straightforward ratio, but the thresholds that separate "healthy" from "will limit your options" are specific enough to be worth checking against real numbers rather than guessing.
The Formula
Total monthly debt payments should include recurring obligations — mortgage or rent, car loans, student loans, minimum credit card payments — but not everyday variable expenses like groceries or utilities, which aren't part of the standard DTI calculation lenders use.
Where This Matters
- Mortgage pre-qualification — most conventional lenders cap back-end DTI around 43%, with the most favorable rates reserved for borrowers well under that line.
- Credit card and personal loan applications — DTI factors into approval odds and offered interest rates for revolving and installment credit beyond mortgages.
- Tracking progress on debt payoff — recalculating DTI as balances are paid down gives a lender's-eye view of improving financial health, distinct from a credit score.
| DTI range | Rating |
|---|---|
| 36% or below | Healthy — viewed favorably |
| 37% – 43% | Manageable — near the typical mortgage maximum |
| 44% – 50% | High — may limit borrowing options |
| Above 50% | Very high — financial strain likely |
Worked Example
$1,850 in monthly debt payments against $6,500 in gross monthly income produces a DTI of 28.46% — within the range lenders generally view as healthy.
How to Use This Calculator
- Enter your total monthly debt payments (mortgage/rent, loans, minimum card payments).
- Enter your gross monthly income (before taxes).
- Select Calculate to see your DTI percentage and how it's typically rated by lenders.
Related Calculations
See the Mortgage Affordability Calculator, which applies DTI-style thresholds directly to estimate a maximum home price, or the Emergency Fund Calculator to build a buffer before taking on new debt.