Understanding debt-to-income ratios

Two ratios, both using gross income

The front-end figure is the estimated housing payment divided by the gross monthly income used in the scenario. The back-end figure adds the monthly debt payments you enter: auto, student, credit-card minimums, personal loans, support, and other recurring debts.

The moderate scenario starts from the housing and total-obligation percentages on the form. Comfortable and stretch use their own percentages. Changing a percentage changes that scenario’s price. It does not change a lender’s guideline, because this page is not reading one.

What is left out

Take-home pay, groceries, utilities, and childcare that you do not type into the debt fields are not in the back-end ratio. A household-expense field, when you use it, reduces only the comfortable housing budget. It is not added to debt-to-income.

A result that fits the ratios you typed can still be unaffordable in a real underwriting review. Credit, the property, reserves, and the lender’s own limits are not checked here.

Needs review before launch. Debt-to-income limits used by agencies and lenders change and are not stored as current quotes on this page.

How to read the two percentages

Open the affordability calculator and change one debt payment. If the moderate price falls, the total-obligation ratio was the tighter limit. If it stays put, the housing ratio or the cash you entered was the limit instead.

The page prints both percentages for the scenario. They describe that scenario. They are not a credit decision.

Try it in a calculator

Related guides

• How much house can I afford?
• Understanding PMI
• How mortgage payments are calculated

Read the methodology

Written to explain how this site’s calculators work. Not a review by a licensed mortgage professional, and not a recommendation to borrow. These notes are not financial, tax, or legal advice.