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Debt-to-Income Ratio

DTI = monthly debt / gross monthly income. Free online Debt-to-Income Ratio for financial — instant, accurate results, mobile-friendly, no signup needed.

DTI
30%

Derivation

  1. ├── 01Givendebt = 1500, income = 5000
  2. ├── 02Formulae.debt / e.income × 100
  3. ├── 03Substitutee.1500 / e.5000 × 100
  4. └── 04Compute DTI30
Did you know?

Ratios appear in the earliest Greek mathematics (Eudoxus, 4th century BCE) as a way to compare incommensurable lengths without a concept of irrational numbers.

§01What is

Understanding the Debt-to-Income Ratio

The Debt-to-Income Ratio computes DTI from 2 inputs: monthly debt ($), gross monthly income ($). DTI = monthly debt / gross monthly income.

Quick calculators for the math that shouldn’t need a notepad — instant, accurate, private to your browser. The Debt-to-Income Ratio sits in that toolkit — it DTI = monthly debt / gross monthly income. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.

§02The Formula

How it’s calculated

e.debt / e.income × 100

Where

debt
Monthly debt ($)
income
Gross monthly income ($)
§03Practical Example

Step-by-step walkthrough

Scenario

Apply the formula to a realistic set of inputs: Monthly debt ($) = 1500, Gross monthly income ($) = 5000.

  1. 01Start by noting the input — Monthly debt ($): 1500.
  2. 02Start by noting the input — Gross monthly income ($): 5000.
  3. 03Substitute these values into the formula: e.debt / e.income × 100
  4. 04Compute DTI: the calculator returns 30.
  5. 05Cross-check the answer by opening the Derivation panel above — every line of math is shown so you can follow the computation end-to-end.
§04Variants

Common Debt-to-Income Ratio Problems

The formula gets rearranged depending on which variable you need. Here are the patterns you’ll run into in the real world — find the one that matches your problem and follow the worked steps.

01 · PATTERN

Monthly debt ($) halved

debt = 750 (from 1500)

Keep every other input at its default and halve the monthly debt ($). See how dti responds.

  1. 01New Monthly debt ($): 750
  2. 02Baseline DTI: 30
  3. 03New DTI: 15
  4. 04DTI decreases by 50% → use this sensitivity to plan for real-world variation.
02 · PATTERN

Monthly debt ($) doubled

debt = 3000 (from 1500)

Keep every other input at its default and double the monthly debt ($). See how dti responds.

  1. 01New Monthly debt ($): 3000
  2. 02Baseline DTI: 30
  3. 03New DTI: 60
  4. 04DTI increases by 100% → use this sensitivity to plan for real-world variation.
03 · PATTERN

Gross monthly income ($) halved

income = 2500 (from 5000)

Keep every other input at its default and halve the gross monthly income ($). See how dti responds.

  1. 01New Gross monthly income ($): 2500
  2. 02Baseline DTI: 30
  3. 03New DTI: 60
  4. 04DTI increases by 100% → use this sensitivity to plan for real-world variation.
04 · PATTERN

Gross monthly income ($) doubled

income = 10000 (from 5000)

Keep every other input at its default and double the gross monthly income ($). See how dti responds.

  1. 01New Gross monthly income ($): 10000
  2. 02Baseline DTI: 30
  3. 03New DTI: 15
  4. 04DTI decreases by 50% → use this sensitivity to plan for real-world variation.
§05FAQ

Frequently asked questions

Yes. The calculator implements the standard formula as documented and returns exact floating-point results. No approximations are used unless noted in the formula.
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