Debt-to-income ratio (DTI) is your recurring monthly debt payments divided by your gross monthly income, expressed as a percentage. Lenders may use it as one input when assessing whether a borrower can manage another payment.
DTI is simple arithmetic, but the inputs are not universal. Different lenders, products and jurisdictions can define qualifying income, included obligations and acceptable ratios differently.
Calculate both scenarios: the Debt-to-Income Ratio Calculator shows the current ratio and the effect of adding a proposed monthly payment without labelling either result approved or affordable.
The debt-to-income formula
DTI = total recurring monthly debt payments ÷ gross monthly income × 100
If gross monthly income is €6,000 and recurring debt payments total €2,000, DTI is 33.3%. Adding a proposed €400 payment raises the modeled debt total to €2,400 and DTI to 40%.
| Scenario | Monthly debt | Gross income | DTI | Gross income after debt |
|---|---|---|---|---|
| Current | €2,000 | €6,000 | 33.3% | €4,000 |
| With proposed payment | €2,400 | €6,000 | 40.0% | €3,600 |
The remaining-income figures are not disposable income. Taxes, food, utilities, insurance, transport, saving and other non-debt costs have not yet been deducted.
Why gross income is normally used
The standard DTI definition uses income before tax and payroll deductions. That makes applications more comparable, but it also means the denominator is not the cash actually available to spend.
Someone with a lower tax burden or fewer essential costs may experience the same DTI differently from someone with identical gross income and debt payments. DTI is therefore a credit-screening ratio, not a complete household budget.
What counts in a DTI calculation?
The exact inputs depend on the lender, product and jurisdiction. This checklist helps separate recurring debt from costs that usually belong in a wider affordability review.
| Treatment | Examples | Why |
|---|---|---|
| Commonly included | Mortgage or housing debt, minimum card payments, car loans, student loans and personal loans | These are recurring contractual debt payments |
| Commonly excluded from DTI | Food, utilities, transport, saving and most ordinary living costs | They matter for affordability but are not normally debts |
| Verify with the lender | Rent, court-ordered obligations, deferred loans, business debt and the proposed new payment | Treatment can vary by application and rule set |
Income is not always straightforward
Salary may be simple to document, while bonuses, commission, overtime, self-employment income, investment income or rent may require a history or adjustment. A lender may not accept every amount entered by a household.
The calculator accepts one gross monthly figure because it cannot verify stability, documentation or lender rules. Use the income that is relevant to the question you are testing, then confirm how the actual lender defines qualifying income.
What is a good debt-to-income ratio?
There is no universal “good” DTI. A lower ratio means less gross income is committed to the debts included in the calculation, but an acceptable limit depends on the lender, loan type and jurisdiction. Published rules of thumb become misleading when separated from the product and rule that produced them.
The Consumer Financial Protection Bureau explicitly notes that DTI limits differ by lender and loan product. Approval can also depend on credit history, assets, deposits, collateral, income stability and the design of the loan.
A ratio below a quoted threshold does not prove a payment is comfortable. A ratio above it does not prove every application will be rejected. The relevant question is which definition and underwriting rule applies to the actual product.
DTI versus a household cash-flow test
DTI starts with gross income and debt obligations. A cash-flow test starts with money received and subtracts all expected outflows. They answer different questions.
| Measure | Compares | Question it helps answer |
|---|---|---|
| Debt-to-income ratio | Recurring monthly debt payments ÷ gross monthly income | How much gross income is committed to recurring debts? |
| Credit utilization | Revolving credit balances ÷ revolving credit limits | How much available revolving credit is being used? |
| Loan-to-income ratio | Loan amount or total debt ÷ annual income, depending on the rule | How large is the balance relative to income? |
| Household cash flow | Cash received minus all modeled outflows | Will income cover debt, living costs and other planned spending? |
DTI is therefore not the same as a debt-to-credit or credit-utilization ratio. One uses monthly payments and income; the other uses revolving balances and credit limits.
Use the Personal Cash Flow Calculator for timing and the Zero-Based Budget Calculator for allocation. Neither should be replaced by a single DTI percentage.
Ways the ratio can change
Mathematically, DTI falls when recurring debt payments fall or qualifying gross income rises. Paying down a balance does not always reduce DTI immediately if the required monthly payment remains unchanged. Refinancing can lower a payment while extending the repayment period and increasing total interest.
That tradeoff is why DTI should be read alongside the remaining balance, interest rate and total cost. The Loan Repayment Calculator separates payment size from modeled lifetime interest.
Methodology and limitations
The formula and example table are original Finance Charts calculations. The definition follows the Consumer Financial Protection Bureau. Finance Charts does not encode a lender’s underwriting rules or recommend a maximum ratio.
- Consumer Financial Protection Bureau — What is a debt-to-income ratio?
- Consumer Financial Protection Bureau — Assessing mortgage affordability
- Finance Charts — Methodology
- Finance Charts — Debt Snowball vs Debt Avalanche
Important: DTI is an arithmetic ratio, not a personalised affordability assessment, lending decision or recommendation to borrow.