How to Calculate Debt-to-Income Ratio
Debt-to-income ratio compares recurring obligations with income before deductions. It can help organize a borrowing conversation, but it cannot replace a take-home budget or tell you that a lender will approve an application.
By USCalcly · Updated
Define the ratio you are measuring
The US Consumer Financial Protection Bureau describes DTI as monthly debt payments divided by gross monthly income. Our calculator separates a housing amount from other monthly obligations so you can see both housing share and the combined ratio.
Record what you included. A planning ratio with current rent is not automatically the same calculation as a mortgage assessment using proposed housing costs. Countries, lenders and products apply their own definitions, income adjustments and affordability checks. The calculator does not impose an approval threshold.
Prepare income on a monthly basis
Use gross income before deductions for the same person or household whose obligations you are entering. Do not mix one person’s salary with both people’s debts unless that is deliberately the scope you want to examine. For variable income, document the period and method used rather than selecting an unusually good month.
For a planning average, annual income divided by 12 gives monthly income. Weekly income multiplied by 52 then divided by 12 gives an annualized monthly average; fortnightly or biweekly income uses 26 pay periods. Twice-monthly income uses 24. These conventions do not guarantee a lender will accept that income or that every calendar month has the same receipts.
Prepare the obligations without double counting
Enter monthly payments, not outstanding loan balances. Put the housing amount relevant to your scenario in the housing field. For a mortgage comparison, obtain the full housing cost components required by the lender, rather than assuming principal and interest are the only components.
Add other required monthly debt payments separately. Keep housing out of that second total. Follow the appropriate instructions for credit cards, student loans, support obligations or other commitments; the calculator cannot infer their treatment. General living costs belong in a separate budget even when they are not part of the debt ratio.
Work through the formula
Total ratio = (housing + other required monthly payments) / gross monthly income × 100. Housing share = housing / gross monthly income × 100.
With income of 6,000, housing of 1,500 and other payments of 600, combined obligations are 2,100. The ratio is 2,100 / 6,000 × 100 = 35%. Housing share is 25%. The remaining 65% is gross income before deductions and other living costs; it is not spare cash.
Test one change at a time
The scenarios below are arithmetic comparisons, not recommended debt levels. Holding other assumptions fixed makes the reason for a change easier to see.
| Gross income | Housing | Other debt | Total ratio |
|---|---|---|---|
| 6,000 | 1,500 | 600 | 35% |
| 6,000 | 1,500 | 300 | 30% |
| 5,000 | 1,500 | 600 | 42% |
| 6,000 | 1,800 | 600 | 40% |
Keep international comparisons honest
The same division works in USD, CAD, GBP or AUD when all entries use one currency. That does not make local lending tests interchangeable. Canadian GDS/TDS, UK affordability and Australian serviceability assessments may use definitions and stress tests beyond this simple ratio. Country selection changes display currency only.
The common errors are mixing annual income with monthly debt, using take-home income in a gross-income ratio, entering balances instead of payments, and assuming a familiar percentage guarantees approval. After calculating, verify definitions with the relevant lender and build a budget from income actually received. The related article shows why two households with identical DTI can have very different cash available.
Common questions
Can the ratio exceed 100%?
Yes. That means the entered monthly obligations exceed entered gross income. Check periods and figures, but the mathematics is still defined.
What if income is zero?
The percentage has no defined denominator. The calculator requires positive gross income instead of returning a misleading zero.
Is this debt balance divided by annual income?
No. That is a different measure. This tool compares monthly payment flows with monthly income flows.
Sources
For informational purposes only. This guide does not provide financial, tax, legal, or investment advice.