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Debt-to-Income Ratio Calculator

Work out your debt-to-income ratio, the number mortgage lenders check first, and see how it compares with the limits FHA and conventional loans actually use.

Enter your gross income and monthly payments to see your debt-to-income ratio.

Income is

Before tax and other deductions, for everyone on the application.

Mortgage principal and interest, property tax, homeowners insurance, mortgage insurance and HOA dues. For a home you are buying, the new payment.

The minimum due, not the balance.

Personal loans, child support, alimony.

All payments are monthly. Leave a debt blank if you do not have it.

Exact calculation. Given your inputs, this is the answer — no estimation involved.

How this calculator works

Your debt-to-income ratio (DTI) is the share of your income before tax that goes to debt payments each month. Lenders use it to judge whether you can take on a mortgage payment as well.

There are two versions. The front-end ratio counts only the housing payment: principal, interest, property tax, homeowners insurance, mortgage insurance and HOA dues. The back-end ratio adds every other monthly debt payment: car loans, student loans, credit card minimums, personal loans, child support and alimony. When people say "DTI" they usually mean the back-end ratio.

Only debts count. Utilities, groceries, phone bills and car insurance are real costs, but they are not debt payments, and lenders leave them out. Income is gross: what you earn before tax and other deductions.

The calculator compares your ratios with the published limits: FHA’s, from HUD’s handbook for manually underwritten loans, and Fannie Mae’s for conventional loans. It also shows the 28/36 rule of thumb, labeled as what it is: a guide to a comfortable budget, not a lending rule.

The formula

Exactly what happens to your numbers, step by step.

  1. Front-end ratio

    housing payment ÷ gross monthly income

  2. Back-end ratio (DTI)

    (housing payment + other debt payments)
÷ gross monthly income

  3. Published limits

    FHA: 31% / 43%, up to 40% / 50%
Fannie Mae: 36%, up to 45%; 50% automated

A worked example

A household earning $7,500 a month before tax, buying a home with a $2,100 monthly payment, with a $450 car payment, $300 of student loans and $150 of card minimums.

What you enter

Gross monthly income
$7,500
Housing payment
$2,100
Other debts
$450 + $300 + $150 = $900

Step by step

Front-end
$2,100 ÷ $7,500 = 28%
Total debt
$2,100 + $900 = $3,000
Back-end
$3,000 ÷ $7,500 = 40%

28% front-end and 40% back-end

That is within FHA’s standard 31% / 43% and inside Fannie Mae’s 45% ceiling with good credit and reserves, but over the 36% Fannie Mae allows without them, and over the 36% rule of thumb. Paying off the $450 car loan would bring the back-end ratio to 34%.

Debt-to-income questions, worked out

The same two divisions every time: housing over income, then all debts over income.

  1. 1.My gross income is $6,000 a month. I pay $1,500 for my mortgage, $100 on a car and $400 on other debts. What is my DTI?

    1. Total debt payments: $1,500 + $100 + $400 = $2,000.
    2. $2,000 ÷ $6,000 = 33.3%.

    33.3%. The housing payment alone is 25% of income.

  2. 2.I earn $72,000 a year. Is a $1,800 mortgage payment with a $350 car payment and $100 of card minimums too much?

    1. Monthly income: $72,000 ÷ 12 = $6,000.
    2. Front-end: $1,800 ÷ $6,000 = 30%.
    3. Back-end: ($1,800 + $350 + $100) ÷ $6,000 = $2,250 ÷ $6,000 = 37.5%.

    30% front-end and 37.5% back-end: over the 28/36 rule of thumb, within FHA’s standard 31/43 and Fannie Mae’s 45% with qualifying credit and reserves.

  3. 3.Does a $1,550 house payment fit FHA limits on $5,000 a month with $600 of other debt?

    1. Front-end: $1,550 ÷ $5,000 = 31%, against FHA’s standard 31%.
    2. Back-end: $2,150 ÷ $5,000 = 43%, against 43%.

    Yes, exactly at both limits: 31% and 43%. FHA’s ratios are maximums, so a ratio equal to the limit qualifies without compensating factors.

  4. 4.I rent and earn $4,200 a month. My car is $380, student loans $260 and cards $90. What is my DTI?

    1. Debt payments: $380 + $260 + $90 = $730.
    2. $730 ÷ $4,200 = 17.4%.

    17.4% before any mortgage. Rent is not a debt, but a lender will add your new mortgage payment when you apply.

Assumptions

Every result here rests on these. Change your inputs and the result changes with them.

  • Payments are monthly, and income is gross: before tax and other deductions.
  • The housing payment is the full payment: principal, interest, property tax, insurance, mortgage insurance and HOA dues.
  • Limits are compared exactly. A ratio that rounds to a limit but is above it is shown as just over.

What this cannot tell you

  • Lenders calculate income their own way, for example averaging two years of self-employment or overtime income, and may count a debt differently, such as using 1% of a student loan balance when the payment is $0. Their figure can differ from yours.
  • FHA limits shown are for manually underwritten loans. Automated underwriting can approve higher ratios, and any lender can set lower limits of its own.
  • A ratio within a limit does not guarantee approval: credit score, reserves, employment and the property all matter too.
  • VA, USDA and jumbo loans have their own rules and are not shown.

Questions people ask

How do I calculate my debt-to-income ratio?

Add up your monthly debt payments and divide by your gross monthly income. The CFPB’s example: a $1,500 mortgage, a $100 car payment and $400 of other debts make $2,000; on $6,000 of monthly income that is a DTI of 33%.

What is a good debt-to-income ratio?

Lower is better, and 36% or less is comfortably inside the main mortgage limits. Fannie Mae allows up to 36% on a manually underwritten loan, 45% with strong credit and reserves, and 50% through its automated system. FHA’s standard limit is 43%.

What is the maximum DTI for an FHA loan?

For a manually underwritten FHA loan, 31% front-end and 43% back-end with no compensating factors, rising to 40% and 50% with two compensating factors such as cash reserves or a minimal increase in housing payment. Borrowers with credit scores below 580 are held to 31% and 43%. Automated underwriting can approve higher ratios.

Is the 43% DTI limit still a rule?

Not for conventional loans in general. A 43% cap used to be part of the federal Qualified Mortgage definition, but the CFPB replaced it with a price-based test in a rule that took full effect in 2022. 43% is still FHA’s standard back-end limit for manually underwritten loans.

Does rent count in my debt-to-income ratio?

Not when you apply for a mortgage: the lender replaces your rent with the new mortgage payment, because that is what you will pay. Rent is a housing cost, not a debt, but it is still worth knowing what share of your income it takes.

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Sources and review

Sources

Methodology version 1.0.0 · Last reviewed

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For coursework, a resource list or your own site. How every calculator is built and checked is set out on the methodology page.

Citation

Chalk Calculator. (2026, October 12). Debt-to-Income Ratio Calculator (Methodology version 1.0.0). https://chalkcalculator.com/debt-to-income-calculator/

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