How it works

A useful distinction

A large balance need not dominate DTI

DTI counts required payments, not debt balances. A 20,000 loan requiring 400 monthly contributes more to the ratio than a 50,000 loan requiring 300; entering balances would answer an entirely different question.

Making income and debt periods comparable

Monthly debt payments of 1,200, 300, and 100 total 1,600. With gross monthly income of 5,000, the modeled debt-to-income ratio is 1,600 ÷ 5,000 × 100 = 32%. Using take-home income of 4,000 would produce 40%, which answers a different question. Enter required debt payments rather than outstanding loan balances. A DTI ratio is not the cash left for living expenses; use the budget worksheet for that, and check the obligations counted by the relevant lender.

Debt-to-income ratio: formula and assumptions

DTI = total monthly debt payments/gross monthly income × 100%.

Different lenders count obligations differently. This is not a lending eligibility determination.

Mixed-period budget & debt ratio: formula and assumptions

Surplus = gross monthly income − pretax saving − modeled tax − living expenses − debt payments.

Each line uses its own monthly or annual period. DTI includes debt payments and uses gross income. The flat tax scenario does not implement progressive income-tax rules.

Worked example

Reference example currency: USD. These fixed examples do not change with your calculator preferences.

Using the Debt-to-income ratio example:

Inputs

Gross monthly income ($): 7000
Monthly housing payment ($): 1800
Other monthly debt payments ($): 500

Method

DTI = total monthly debt payments/gross monthly income × 100%.

Result

Example result

Total debt-to-income ratio: 32.86%

Housing ratio: 25.71%

These are illustrative inputs. Change the values to explore a different scenario.

Formula references

References explain the underlying methods; they do not imply endorsement or individual professional review of Finflo.

Common questions

Should I use income before or after tax for DTI?

Use gross income before tax. The mixed-period budget’s spendable-income result is separate from the gross-income denominator used for DTI.

Can I enter annual debt or income amounts?

Yes. The mixed-period mode normalizes each annual amount to one-twelfth before calculating the ratio.

Does the result establish loan eligibility?

No. Lenders may count income and obligations differently; use the debts relevant to the comparison.

Prepared by Finflo. See our methodology and editorial policy. Read the relevant professional-advice limitations.

Debt-to-Income (DTI) Ratio Calculator

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